Dynamics of cosmological relaxation after reheating

Transcription

1 Dynamics of cosmological relaxation after reheating Hyungjin Kim KAIST & IBS CTPU The 3rd IBS-MultiDark-IPPP Workshop November

2 [Graham, Kaplan, Rajendran 15]

3 m 2 h( 0 ) (90 GeV) 2 [Graham, Kaplan, Rajendran 15]

4 Necessary ingredients for relaxion are Relaxion dependent Higgs mass Higgs vev dependent Back-reaction potential Inflationary Hubble friction [Graham, Kaplan, Rajendran 15]

5 Whole scanning process take place during inflation What happens after the reheating?

6 Two possible scenarios Reheating temperature lower than electroweak scale Reheating temperature higher than electroweak scale

7 Two possible scenarios Reheating temperature lower than electroweak scale thermal correction is small barrier is still there relaxion does not evolve Reheating temperature higher than electroweak scale

8 Two possible scenarios Reheating temperature lower than electroweak scale thermal correction is small barrier is still there relaxion does not evolve Reheating temperature higher than electroweak scale thermal correction is large gauge symmetry is restored barrier disappears relaxion evolves!

9 (positive)

10 (positive)

11 To preserve successful selection of electroweak scale we need small enough field velocity

12 To preserve successful selection of electroweak scale, we require otherwise, the selection of electroweak scale is easily ruined

13 Dynamically selected EW scale is not stable against high reheating temperature Alternative possibility?

14 A possibility: A new frictional force from Abelian gauge boson [Choi, HK, Toyokazu; Work in progress]

15 A possibility: A new frictional force from Abelian gauge boson Friction from Hubble Friction from gauge field production [Choi, HK, Toyokazu; Work in progress]

16 A possibility: A new frictional force from Abelian gauge boson [Choi, HK, Toyokazu; Work in progress]

17 Anomalous coupling time-dependent coupling breaks conformal invariance and develops instability of gauge boson [Anber & Sorbo, 09]

18 Dispersion relation for propagating mode tachyonic mode

19 Dispersion relation tachyonic mode exists for & and exponentially grows in time

20 Background evolution of scalar field develops instability and exponentially produces gauge bosons Produce X

21 Background evolution of scalar field develops instability and exponentially produces gauge bosons modifies Produce X How does X field modify the field velocity of relaxion?

22 Evolution of scalar field

23 Evolution of scalar field force

24 Evolution of scalar field velocity-dependent friction

25 Evolution of scalar field gauge friction

26 Evolution of scalar field terminal velocity is determined as = FX H

27 Evolution of scalar field terminal velocity is determined as = FX H decreasing function in time!

28 When does it stop? barrier is formed at T T c 2 apple 4 b?

29 When does it stop? barrier is formed at T T c 2 apple 4 b? Yes relaxion stops at T c

30 When does it stop? barrier is formed at T T c 2 apple 4 b? Yes relaxion stops at T c No relaxion stops at T b * Tb is when 2 (T b ) 4 b

31 When does it stop? barrier is formed at T T c 2 apple 4 b? Yes relaxion stops at T c No relaxion stops at T b * Tb is when 2 (T b ) 4 b relaxion will stop at T s =min(t c,t b )

32 To preserve successful selection of electroweak scale ( V (t s ) V apple 2 v 2

33 To preserve successful selection of electroweak scale ( V (t s ) V apple T 4 s apple 2 v 2 To prevent overproduction of dark gauge boson

34 Preliminary h = h = N e h = Gauge field overproduction [Choi, HK, Toyokazu; Work in progress]

35 h = Preliminary Fifth force h = N e h = SN1978A Gauge field overproduction

36 h = h = h = 10 5 Preliminary Fifth force N e 0.3 Gauge field overproduction Globular Cluster SN1978A LHC regarding constraints on relaxion scenario [Choi & Im 16] [Flacke et. al. 16]

37 Conclusion 1. High reheating temperature is dangerous for cosmological relaxation 2. If relaxion has anomalous coupling to Abelian gauge boson, it transfer its kinetic energy into gauge bosons 3. Field velocity approaches to terminal velocity, 4. The relaxion can be re-captured by back-reaction potential at EWPT under reasonable choice of parameters