1. Extra Dimensional Models with Magnetic Fluxes Tatsuo Kobayashi １． Introduction 2. Magnetized extra dimensions 3. N-point couplings and flavor symmetries 4 ． Models 5. Summary based on based on Abe, T.K., Ohki, arXiv: 0806.4748 Abe, T.K., Ohki, arXiv: 0806.4748 Abe, Choi, T.K., Ohki, 0812.3534, 0903.3800, 0904.2631, 0907.5274, Abe, Choi, T.K., Ohki, 0812.3534, 0903.3800, 0904.2631, 0907.5274, Choi, T.K., Maruyama, Murata, Nakai, Ohki, Sakai, 0908.0395 Choi, T.K., Maruyama, Murata, Nakai, Ohki, Sakai, 0908.0395 T.K., Maruyama, Murata, Ohki, Sakai, 1002.2828 T.K., Maruyama, Murata, Ohki, Sakai, 1002.2828

2. １ Introduction 1-1. Introduction to higher D theory Extra dimensional field theories, in particular in particular string-derived extra dimensional field theories, string-derived extra dimensional field theories, play important roles in particle physics play important roles in particle physics as well as cosmology. as well as cosmology.

3. Extra dimensions 4 + n dimensions 4 + n dimensions 4D ⇒ our 4D space-time 4D ⇒ our 4D space-time nD ⇒ compact space nD ⇒ compact space Examples of compact space torus, orbifold, CY, etc. torus, orbifold, CY, etc.

4. Field theory in higher dimensions 10D ⇒ 4D our space-time + 6D space 10D ⇒ 4D our space-time + 6D space 10D vector 10D vector 4D vector + 4D scalars 4D vector + 4D scalars SO(10) spinor ⇒ SO(4) spinor x SO(6) spinor x SO(6) spinor internal quantum number internal quantum number

5. Field theory in higher dimensions Mode expansions Mode expansions KK decomposition KK decomposition

6. Zero-modes Zero-mode equation ⇒ non-trival zero-mode profile the number of zero-modes the number of zero-modes

7. 4D effective theory Higher dimensional Lagrangian (e.g. 10D) integrate the compact space ⇒ 4D theory integrate the compact space ⇒ 4D theory Coupling is obtained by the overlap integral of wavefunctions integral of wavefunctions

8. Couplings in 4D Zero-mode profiles are quasi-localized Zero-mode profiles are quasi-localized far away from each other in compact space far away from each other in compact space ⇒ suppressed couplings ⇒ suppressed couplings

9. 1-2. Introduction to magnetized torus Chiral theory When we start with extra dimensional field theories, how to realize chiral theories is one of important issues from the viewpoint of particle physics. how to realize chiral theories is one of important issues from the viewpoint of particle physics. Zero-modes between chiral and anti-chiral fields are different from each other fields are different from each other on certain backgrounds, e.g. CY. on certain backgrounds, e.g. CY.

10. Torus with magnetic flux The limited number of solutions with non-trivial backgrounds are known. non-trivial backgrounds are known. Torus background with magnetic flux is one of interesting backgrounds, is one of interesting backgrounds, where one can solve zero-mode where one can solve zero-mode Dirac equation. Dirac equation.

11. Magnetic flux Indeed, several studies have been done in both extra dimensional field theories in both extra dimensional field theories and string theories with magnetic flux and string theories with magnetic flux background. background. In particular, magnetized D-brane models are T-duals of intersecting D-brane models. are T-duals of intersecting D-brane models. Several interesting models have been constructed in intersecting D-brane models, constructed in intersecting D-brane models, that is, the starting theory is U(N) SYM. that is, the starting theory is U(N) SYM.

12. Magnetized extra dimensions The (generation) number of zero-modes is determined by the size of magnetic flux. is determined by the size of magnetic flux. Zero-mode profiles are quasi-localized. => several interesting phenomenology => several interesting phenomenology

13. Phenomenology of magnetized brane models It is important to study phenomenological aspects of magnetized brane models such as aspects of magnetized brane models such as massless spectra from several gauge groups, massless spectra from several gauge groups, U(N), SO(N), E6, E7, E8,... U(N), SO(N), E6, E7, E8,... Yukawa couplings and higher order n-point Yukawa couplings and higher order n-point couplings in 4D effective theory, couplings in 4D effective theory, their symmetries like flavor symmetries, their symmetries like flavor symmetries, Kahler metric, etc. Kahler metric, etc. It is also important to extend such studies on torus background to other backgrounds on torus background to other backgrounds with magnetic fluxes, e.g. orbifold backgrounds. with magnetic fluxes, e.g. orbifold backgrounds.

14. 2. Extra dimensions with magnetic fluxes: basic tools 2-1. Magnetized torus model 2-1. Magnetized torus model We start with N=1 super Yang-Mills theory We start with N=1 super Yang-Mills theory in D = 4+2n dimensions. in D = 4+2n dimensions. For example, 10D super YM theory For example, 10D super YM theory consists of gauge bosons (10D vector) consists of gauge bosons (10D vector) and adjoint fermions (10D spinor). and adjoint fermions (10D spinor). We consider 2n-dimensional torus compactification with magnetic flux background. with magnetic flux background.

15. Higher Dimensional SYM theory with flux Cremades, Ibanez, Marchesano, ‘ 04 The wave functions eigenstates of corresponding internal Dirac/Laplace operator. 4D Effective theory <= dimensional reduction

16. Higher Dimensional SYM theory with flux Abelian gauge field on magnetized torus Constant magnetic flux The boundary conditions on torus (transformation under torus translations) gauge fields of background

17. Dirac equation on 2D torus with twisted boundary conditions (Q=1) is the two component spinor.

18. |M| independent zero mode solutions in Dirac equation. (Theta function) Dirac equation and chiral fermion Properties of theta functions :Normalizable mode :Non-normalizable mode By introducing magnetic flux, we can obtain chiral theory. chiral fermion

19. Wave functions Wave function profile on toroidal background For the case of M=3 Zero-modes wave functions are quasi-localized far away each other in extra dimensions. Therefore the hierarchirally small Yukawa couplings may be obtained.

20. Fermions in bifundamentals The gaugino fields Breaking the gauge group bi-fundamental matter fields gaugino of unbroken gauge (Abelian flux case )

21. Bi-fundamental Gaugino fields in off-diagonal entries correspond to bi-fundamental matter fields correspond to bi-fundamental matter fields and the difference M= m-m ’ of magnetic and the difference M= m-m ’ of magnetic fluxes appears in their Dirac equation. fluxes appears in their Dirac equation. F

22. Zero-modes Dirac equations Total number of zero-modes of :Normalizable mode :Non-Normalizable mode No effect due to magnetic flux for adjoint matter fields,

23. 4D chiral theory 10D spinor 10D spinor light-cone 8s light-cone 8s even number of minus signs even number of minus signs 1 st ⇒ 4D, the other ⇒ 6D space 1 st ⇒ 4D, the other ⇒ 6D space If all of appear If all of appear in 4D theory, that is non-chiral theory. in 4D theory, that is non-chiral theory. If for all torus, If for all torus, only only appear for 4D helicity fixed. appear for 4D helicity fixed. ⇒ 4D chiral theory ⇒ 4D chiral theory

24. U(8) SYM theory on T6 Pati-Salam group up to U(1) factors Three families of matter fields with many Higgs fields

25. 2-2. Wilson lines Cremades, Ibanez, Marchesano, ’ 04, Cremades, Ibanez, Marchesano, ’ 04, Abe, Choi, T.K. Ohki, ‘ 09 Abe, Choi, T.K. Ohki, ‘ 09 torus without magnetic flux torus without magnetic flux constant Ai  mass shift constant Ai  mass shift every modes massive every modes massive magnetic flux magnetic flux the number of zero-modes is the same. the number of zero-modes is the same. the profile: f(y)  f(y +a/M) the profile: f(y)  f(y +a/M) with proper b.c. with proper b.c.

26. U(1)a*U(1)b theory magnetic flux, Fa=2πM, Fb=0 magnetic flux, Fa=2πM, Fb=0 Wilson line, Aa=0, Ab=C Wilson line, Aa=0, Ab=C matter fermions with U(1) charges, (Qa,Qb) matter fermions with U(1) charges, (Qa,Qb) chiral spectrum, chiral spectrum, for Qa=0, massive due to nonvanishing WL for Qa=0, massive due to nonvanishing WL when MQa >0, the number of zero-modes when MQa >0, the number of zero-modes is MQa. is MQa. zero-mode profile is shifted depending zero-mode profile is shifted depending on Qb, on Qb,

27. 2.3 Orbifold with magnetic flux Abe, T.K., Ohki, ‘ 08 Abe, T.K., Ohki, ‘ 08 The number of even and odd zero-modes The number of even and odd zero-modes We can also embed Z2 into the gauge space. We can also embed Z2 into the gauge space. => various models, various flavor structures => various models, various flavor structures

28. Zero-modes on orbifold Adjoint matter fields are projected by orbifold projection. orbifold projection. We have degree of freedom to introduce localized modes on fixed points introduce localized modes on fixed points like quarks/leptons and higgs fields. like quarks/leptons and higgs fields.

29. 3.N-point couplings and flavor symmetries The N-point couplings are obtained by The N-point couplings are obtained by overlap integral of their zero-mode w.f. ’ s. overlap integral of their zero-mode w.f. ’ s.

30. Zero-modes Cremades, Ibanez, Marchesano, ‘ 04 Cremades, Ibanez, Marchesano, ‘ 04 Zero-mode w.f. = gaussian x theta-function Zero-mode w.f. = gaussian x theta-function up to normalization factor up to normalization factor

31. 3-point couplings Cremades, Ibanez, Marchesano, ‘ 04 Cremades, Ibanez, Marchesano, ‘ 04 The 3-point couplings are obtained by The 3-point couplings are obtained by overlap integral of three zero-mode w.f. ’ s. overlap integral of three zero-mode w.f. ’ s. up to normalization factor up to normalization factor

32. Selection rule Each zero-mode has a Zg charge, Each zero-mode has a Zg charge, which is conserved in 3-point couplings. which is conserved in 3-point couplings. up to normalization factor up to normalization factor

33. 4-point couplings Abe, Choi, T.K., Ohki, ‘ 09 Abe, Choi, T.K., Ohki, ‘ 09 The 4-point couplings are obtained by The 4-point couplings are obtained by overlap integral of four zero-mode w.f. ’ s. overlap integral of four zero-mode w.f. ’ s. split insert a complete set insert a complete set up to normalization factor up to normalization factor for K=M+N for K=M+N

34. 4-point couplings: another splitting i k i k i k i k t j s l j l j s l j l

35. N-point couplings Abe, Choi, T.K., Ohki, ‘ 09 Abe, Choi, T.K., Ohki, ‘ 09 We can extend this analysis to generic n-point couplings. We can extend this analysis to generic n-point couplings. N-point couplings = products of 3-point couplings N-point couplings = products of 3-point couplings = products of theta-functions = products of theta-functions This behavior is non-trivial. (It ’ s like CFT.) Such a behavior would be satisfied Such a behavior would be satisfied not for generic w.f. ’ s, but for specific w.f. ’ s. not for generic w.f. ’ s, but for specific w.f. ’ s. However, this behavior could be expected However, this behavior could be expected from T-duality between magnetized from T-duality between magnetized and intersecting D-brane models. and intersecting D-brane models.

36. T-duality The 3-point couplings coincide between The 3-point couplings coincide between magnetized and intersecting D-brane models. magnetized and intersecting D-brane models. explicit calculation explicit calculation Cremades, Ibanez, Marchesano, ‘ 04 Cremades, Ibanez, Marchesano, ‘ 04 Such correspondence can be extended to Such correspondence can be extended to 4-point and higher order couplings because of 4-point and higher order couplings because of CFT-like behaviors, e.g., CFT-like behaviors, e.g., Abe, Choi, T.K., Ohki, ‘ 09 Abe, Choi, T.K., Ohki, ‘ 09

37. Heterotic orbifold models Our results would be useful to n-point couplings Our results would be useful to n-point couplings of twsited sectors in heterotic orbifold models. of twsited sectors in heterotic orbifold models. Twisted strings on fixed points might correspond Twisted strings on fixed points might correspond to quasi-localized modes with magnetic flux, to quasi-localized modes with magnetic flux, zero modes profile = gaussian x theta-function zero modes profile = gaussian x theta-function

38. Non-Abelian discrete flavor symmetry The coupling selection rule is controlled by Zg charges. Zg charges. For M=g, 1 2 g For M=g, 1 2 g Effective field theory also has a cyclic permutation symmetry of g zero-modes. Effective field theory also has a cyclic permutation symmetry of g zero-modes. These lead to non-Abelian flavor symmetires such as D4 and Δ(27) such as D4 and Δ(27) Cf. heterotic orbifolds, T.K. Raby, Zhang, ’ 04 Cf. heterotic orbifolds, T.K. Raby, Zhang, ’ 04 T.K. Nilles, Ploger, Raby, Ratz, ‘ 06 T.K. Nilles, Ploger, Raby, Ratz, ‘ 06

39. 3. Models We can construct several models by using We can construct several models by using the above model building tools. the above model building tools. What is the starting theory ? What is the starting theory ? 10D SYM or 6D SYM (+ hyper multiplets), 10D SYM or 6D SYM (+ hyper multiplets), gauge groups, U(N), SO(N), E6, E7,E8,... gauge groups, U(N), SO(N), E6, E7,E8,... What is the gauge background ? What is the gauge background ? the form of magnetic fluxes, Wilson lines. the form of magnetic fluxes, Wilson lines. What is the geometrical background ? What is the geometrical background ? torus, orbifold, etc. torus, orbifold, etc.

40. E6 SYM theory on T6 Choi, et. al. ‘ 09 Choi, et. al. ‘ 09 We introduce magnetix flux along U(1) direction, We introduce magnetix flux along U(1) direction, which breaks E6 -> SO(10)*U(1) which breaks E6 -> SO(10)*U(1) Three families of chiral matter fields 16 We introduce Wilson lines breaking We introduce Wilson lines breaking SO(10) -> SM group. SO(10) -> SM group. Three families of quarks and leptons matter fields with no Higgs fields with no Higgs fields

41. Splitting zero-mode profiles Wilson lines do not change the (generation) number of zero-modes, but change localization point. 16 16 Q …… L Q …… L

42. E8 SYM theory on T6 T.K., et. al. 1002:2828 T.K., et. al. 1002:2828 E8 -> SU(3)*SU(2)*U(1) Y *U(1) 1 *U(1) 2 *U(1) 3 *U(1) 4 E8 -> SU(3)*SU(2)*U(1) Y *U(1) 1 *U(1) 2 *U(1) 3 *U(1) 4 We introduce magnetic fluxes and Wilson lines We introduce magnetic fluxes and Wilson lines along five U(1) ’ s. along five U(1) ’ s. E8 248 adjoint rep. include various matter fields. E8 248 adjoint rep. include various matter fields. 248 = (3,2) (1,1,0,1,-1) + (3,2) (1,0,1,1,-1) + (3,2) (1,-1,-1,1,-1) 248 = (3,2) (1,1,0,1,-1) + (3,2) (1,0,1,1,-1) + (3,2) (1,-1,-1,1,-1) + (3,2) (1,1,0,1,-1) + (3,2) (1,0,1,1,-1) +...... + (3,2) (1,1,0,1,-1) + (3,2) (1,0,1,1,-1) +...... We have studied systematically the possibilities We have studied systematically the possibilities for realizing the MSSM. for realizing the MSSM.

43. Results: E8 SYM theory on T6 1. 1. We can get exactly 3 generations of We can get exactly 3 generations of quarks and leptons, quarks and leptons, but there are tachyonic modes and no top Yukawa. but there are tachyonic modes and no top Yukawa. 2. 2. We allow MSSM + vector-like generations We allow MSSM + vector-like generations and require the top Yukawa couplings and and require the top Yukawa couplings and no exotic fields no exotic fields as well as no vector-like quark doublets. as well as no vector-like quark doublets.  three classes  three classes

44. Results: E8 SYM theory on T6 A. A.B. C.

45. Results: E8 SYM theory on T6 There are many vector-like generations. There are many vector-like generations. They have 3- and 4-point couplings with They have 3- and 4-point couplings with singlets (with no hypercharges). singlets (with no hypercharges). VEVs of singlets  mass terms of vector-like VEVs of singlets  mass terms of vector-like generations generations Light modes depend on such mass terms. That is, low-energy phenomenologies That is, low-energy phenomenologies depends on VEVs of singlets (moduli). depends on VEVs of singlets (moduli).

46. Results: E8 SYM theory on T6 It would be interesting to reduce the number It would be interesting to reduce the number of vector-like generations. of vector-like generations. orbifolding and/or non-Abelian Wilson lines orbifolding and/or non-Abelian Wilson lines

47. Summary We have studied phenomenological aspects of magnetized brane models. of magnetized brane models. Model building from U(N), E6, E7, E8 Model building from U(N), E6, E7, E8 N-point couplings are comupted. N-point couplings are comupted. 4D effective field theory has non-Abelian flavor 4D effective field theory has non-Abelian flavor symmetries, e.g. D4, Δ(27). symmetries, e.g. D4, Δ(27). Orbifold background with magnetic flux is Orbifold background with magnetic flux is also important. also important.