space-time picture of schwinger...

15
Space-time picture of Schwinger mechanism Non-perturbative pair creation under a color electric field Time-evolution with back reaction Effects of a magnetic field Naoto Tanji Univ. of Tokyo, Komaba discussion session with Prof. Blaizot, 09.11.18

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Page 1: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Space-time picture of Schwinger mechanism

bull Non-perturbative pair creation under a color electric fieldbull Time-evolution with back reactionbull Effects of a magnetic field

Naoto TanjiUniv of Tokyo Komaba

discussion session with Prof Blaizot 091118

Initial stage of heavy-ion collision

How classical fields evolve1 classical time-evolution

2 quantum effects

bull expansion of the system bull instability bull back reaction

bull non-perturbative pair creation (Schwinger mechanism)

Need to describe the time-evolution of a system whereclassical fields and quantum fields interact with each other

bull interaction between quanta

time evolution

classical color electric fields in the longitudinal direction

bull the Low-Nussinov modelbull the color glass condensate

Initial stage of heavy-ion collision

classical color electric fields in the longitudinal direction

bull the Low-Nussinov modelbull the color glass condensate

How classical fields evolve1 classical time-evolution

2 quantum effects

bull expansion of the system bull instability bull back reaction

bull non-perturbative pair creation (Schwinger mechanism)

bull Effects of color magnetic fields on pair creation

Need to describe the time-evolution of a system whereclassical fields and quantum fields interact with each other

bull interaction between quanta

bull Dynamical view of quark pair creation in uniform color electric fields

Also longitudinalmagnetic field

ElectricMagnetic

time evolution

Formalism

QCD Lagrangian

Separate the gauge field

classical field quantum field

Eq of motion for the quantum gauge field

Eq of motion for the quark field

Eq of motion for the classical gauge field (ldquoMaxwellrdquo eq)

spin-electromagnetic field interaction

current generated by quarks and gluons

Abelianization

a constant vector indicating a color direction of electromagnetic fields

diagonalize

rotating weightroot diagram

Each quark field couples to the Abelianized gauge field via coupling

Relation between and

gauge (Casimir) invariant quantitycharacterizing a color direction (Nayak 2005)

There are two independent directionsin SU(3) color space which are parameterizedby and in a gauge-invariant way

Assume a spatially uniform color electric field

Quantization in background fields

z

t

0

evo

lve

positive frequency

switch-on

superposition of positive and negative frequency

Quantization in background fields

z

t

0

evo

lve

superposition of positive and negative frequency

time-dependent Bogoliubov transformation

is non-zero

Numerical result

longitudinal momentum distribution

current density electric field number density

plasma oscillation

Pauli blocking

( initial field strength)

(quark pair creation)

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 2: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Initial stage of heavy-ion collision

How classical fields evolve1 classical time-evolution

2 quantum effects

bull expansion of the system bull instability bull back reaction

bull non-perturbative pair creation (Schwinger mechanism)

Need to describe the time-evolution of a system whereclassical fields and quantum fields interact with each other

bull interaction between quanta

time evolution

classical color electric fields in the longitudinal direction

bull the Low-Nussinov modelbull the color glass condensate

Initial stage of heavy-ion collision

classical color electric fields in the longitudinal direction

bull the Low-Nussinov modelbull the color glass condensate

How classical fields evolve1 classical time-evolution

2 quantum effects

bull expansion of the system bull instability bull back reaction

bull non-perturbative pair creation (Schwinger mechanism)

bull Effects of color magnetic fields on pair creation

Need to describe the time-evolution of a system whereclassical fields and quantum fields interact with each other

bull interaction between quanta

bull Dynamical view of quark pair creation in uniform color electric fields

Also longitudinalmagnetic field

ElectricMagnetic

time evolution

Formalism

QCD Lagrangian

Separate the gauge field

classical field quantum field

Eq of motion for the quantum gauge field

Eq of motion for the quark field

Eq of motion for the classical gauge field (ldquoMaxwellrdquo eq)

spin-electromagnetic field interaction

current generated by quarks and gluons

Abelianization

a constant vector indicating a color direction of electromagnetic fields

diagonalize

rotating weightroot diagram

Each quark field couples to the Abelianized gauge field via coupling

Relation between and

gauge (Casimir) invariant quantitycharacterizing a color direction (Nayak 2005)

There are two independent directionsin SU(3) color space which are parameterizedby and in a gauge-invariant way

Assume a spatially uniform color electric field

Quantization in background fields

z

t

0

evo

lve

positive frequency

switch-on

superposition of positive and negative frequency

Quantization in background fields

z

t

0

evo

lve

superposition of positive and negative frequency

time-dependent Bogoliubov transformation

is non-zero

Numerical result

longitudinal momentum distribution

current density electric field number density

plasma oscillation

Pauli blocking

( initial field strength)

(quark pair creation)

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 3: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Initial stage of heavy-ion collision

classical color electric fields in the longitudinal direction

bull the Low-Nussinov modelbull the color glass condensate

How classical fields evolve1 classical time-evolution

2 quantum effects

bull expansion of the system bull instability bull back reaction

bull non-perturbative pair creation (Schwinger mechanism)

bull Effects of color magnetic fields on pair creation

Need to describe the time-evolution of a system whereclassical fields and quantum fields interact with each other

bull interaction between quanta

bull Dynamical view of quark pair creation in uniform color electric fields

Also longitudinalmagnetic field

ElectricMagnetic

time evolution

Formalism

QCD Lagrangian

Separate the gauge field

classical field quantum field

Eq of motion for the quantum gauge field

Eq of motion for the quark field

Eq of motion for the classical gauge field (ldquoMaxwellrdquo eq)

spin-electromagnetic field interaction

current generated by quarks and gluons

Abelianization

a constant vector indicating a color direction of electromagnetic fields

diagonalize

rotating weightroot diagram

Each quark field couples to the Abelianized gauge field via coupling

Relation between and

gauge (Casimir) invariant quantitycharacterizing a color direction (Nayak 2005)

There are two independent directionsin SU(3) color space which are parameterizedby and in a gauge-invariant way

Assume a spatially uniform color electric field

Quantization in background fields

z

t

0

evo

lve

positive frequency

switch-on

superposition of positive and negative frequency

Quantization in background fields

z

t

0

evo

lve

superposition of positive and negative frequency

time-dependent Bogoliubov transformation

is non-zero

Numerical result

longitudinal momentum distribution

current density electric field number density

plasma oscillation

Pauli blocking

( initial field strength)

(quark pair creation)

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 4: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Formalism

QCD Lagrangian

Separate the gauge field

classical field quantum field

Eq of motion for the quantum gauge field

Eq of motion for the quark field

Eq of motion for the classical gauge field (ldquoMaxwellrdquo eq)

spin-electromagnetic field interaction

current generated by quarks and gluons

Abelianization

a constant vector indicating a color direction of electromagnetic fields

diagonalize

rotating weightroot diagram

Each quark field couples to the Abelianized gauge field via coupling

Relation between and

gauge (Casimir) invariant quantitycharacterizing a color direction (Nayak 2005)

There are two independent directionsin SU(3) color space which are parameterizedby and in a gauge-invariant way

Assume a spatially uniform color electric field

Quantization in background fields

z

t

0

evo

lve

positive frequency

switch-on

superposition of positive and negative frequency

Quantization in background fields

z

t

0

evo

lve

superposition of positive and negative frequency

time-dependent Bogoliubov transformation

is non-zero

Numerical result

longitudinal momentum distribution

current density electric field number density

plasma oscillation

Pauli blocking

( initial field strength)

(quark pair creation)

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 5: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Abelianization

a constant vector indicating a color direction of electromagnetic fields

diagonalize

rotating weightroot diagram

Each quark field couples to the Abelianized gauge field via coupling

Relation between and

gauge (Casimir) invariant quantitycharacterizing a color direction (Nayak 2005)

There are two independent directionsin SU(3) color space which are parameterizedby and in a gauge-invariant way

Assume a spatially uniform color electric field

Quantization in background fields

z

t

0

evo

lve

positive frequency

switch-on

superposition of positive and negative frequency

Quantization in background fields

z

t

0

evo

lve

superposition of positive and negative frequency

time-dependent Bogoliubov transformation

is non-zero

Numerical result

longitudinal momentum distribution

current density electric field number density

plasma oscillation

Pauli blocking

( initial field strength)

(quark pair creation)

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 6: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Quantization in background fields

z

t

0

evo

lve

positive frequency

switch-on

superposition of positive and negative frequency

Quantization in background fields

z

t

0

evo

lve

superposition of positive and negative frequency

time-dependent Bogoliubov transformation

is non-zero

Numerical result

longitudinal momentum distribution

current density electric field number density

plasma oscillation

Pauli blocking

( initial field strength)

(quark pair creation)

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 7: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Quantization in background fields

z

t

0

evo

lve

superposition of positive and negative frequency

time-dependent Bogoliubov transformation

is non-zero

Numerical result

longitudinal momentum distribution

current density electric field number density

plasma oscillation

Pauli blocking

( initial field strength)

(quark pair creation)

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 8: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Numerical result

longitudinal momentum distribution

current density electric field number density

plasma oscillation

Pauli blocking

( initial field strength)

(quark pair creation)

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 9: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Pressure

The initial state with the longitudinal electric field is quite anisotropic

In local thermalized QGP pressure must be isotropicHow does the system become isotropic

energy-momentum tensor

It is worthwhile to investigate how pressure evolves due to pair creationalthough full isotropization cannot be achieved in our treatment

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 10: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

L particleT particleL fieldT field

pressure

pressure

L totalT total

Pressure

Degree of anisotropy is moderated by pair creation

Created particles generate positive longitudinal pressure

Due to back reactionthe field strength is weakened

Negative longitudinal pressure is compensated by pressure generated by particles

total pressure

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 11: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

bull Landau level

01

3

5

7

continuous spectrum spin 0 spin 12

bull Zeeman splitting

lowest level

The strong magnetic field makes particles ldquoheavyrdquo and suppresses pair creation

The effects of a magnetic field

Longitudinal magnetic field

Pair creation is not suppressed

The number of modes degenerating in one Landau level is proportional to B

ElectricMagnetic

ldquoheavyrdquo

ldquolightrdquo

independent of B

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 12: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Pair creation is enhanced Time evolution gets faster

The effects of a magnetic field1 Enhancement of pair creation

current density electric field number density

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 13: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

The effects of a magnetic field2 Induction of chiral charge

01

3

5

Lan

dau

leve

l

Due to spin-magnetic field interactionenergy levels are split

The lowest Landau level induces chiral charge

The Adler-Bell-Jackiw anomaly equation

explicit breaking of chiral symmetryby nonzero mass

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 14: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

nonzero mass massless

The time evolution of chiral charge

The effects of a magnetic field2 Induction of chiral charge

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge

Page 15: Space-time picture of Schwinger mechanismnt1.c.u-tokyo.ac.jp/about/seminar/2009/JPB_tanji.pdfSpace-time picture of Schwinger mechanism •Non-perturbative pair creation under a color

Summary

bull The momentum distributions of created quarks and their time-evolution in uniform color electric fields have been revealed

bull Negative longitudinal pressure of the electric field is compensatedby pressure of created particles

bull The magnetic field speeds up the time-evolution of the quark systemand induces chiral charge