Motohiko Kusakabe 1,2 collaborators K. S. Kim 1, Myung-Ki Cheoun 2, Seoktae Koh 3, A. B. Balantekin...
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Motohiko Kusakabe 1,2 collaborators K. S. Kim 1, Myung-Ki Cheoun 2, Seoktae Koh 3, A. B. Balantekin 4, Toshitaka Kajino 5,6,Y. Pehlivan 7, Hiroyuki Ishida
Motohiko Kusakabe 1,2 collaborators K. S. Kim 1, Myung-Ki
Cheoun 2, Seoktae Koh 3, A. B. Balantekin 4, Toshitaka Kajino
5,6,Y. Pehlivan 7, Hiroyuki Ishida 8,Hiroshi Okada 9 1 Korea
Aerospace Univ., 2 Soongsil Univ., 3 Jeju National Univ., 4 Univ.
Wisconsin, Madison, 5 National Astronomical Observatory of Japan, 6
Univ. Tokyo, 7 Mimar Sinan Fine Arts Univ., 8 Tohoku Univ., 9 KIAS
2015/3/20 Effects of sterile neutrino and modified gravity on
primordial nucleosynthesis Workshop on Neutrino Physics and
Astrophysics
Slide 2
Introduction 1. Solar abundance H, He (big bang
nucleosynthesis; BBN) Nucl. SE (supernova Ia) Ne, Si, S, Ca (C, O,
Si burning in massive star) Li, Be, B (cosmic ray spallation+) Ryan
(2000)
Slide 3
Prediction in standard BBN model (Coc et al., 2012) Ryan (2000)
1. Solar abundance Galactic chemical evolution Interstellar matter
massive star Cosmic ray from supernova spallation Production after
BBN
Slide 4
Ryan (2000) Li, Be, B (cosmic ray spallation+) Light elements:
good probe of the early universe 1. Solar abundance Prediction in
standard BBN model (Coc et al., 2012)
Slide 5
Standard BBN parameter: baryon-to-photon ratio CMB constraint
on Observation of metal-poor stars (MPSs) 7 Li abundance is smaller
than theory by a factor of ~3 Primordial abundances of Be, B, are
not detected yet. ESA and the Planck Collaboration Izotov et al.
(2014) Cooke et al. (2014) Bania et al. (2002) Sbordone et al.
(2010) Lind et al. (2013) 2. Primordial light element
abundances
Slide 6
7 Li/H in MPSs < 7 Li/H in SBBN 7 Li/H=(1.1-1.5)10 -10 fit
of LiI 6708 A line (Spite & Spite 1982, Ryan et al. 2000,
Melendez & Ramirez 2004, Asplund et al. 2006, Bonifacio et al.
2007, Shi et al. 2007, Aoki et al. 2009, Sbordone 2010) 7 Li BBN 3.
Li problem Asplund06 Sbordone10 Aoki09 Gonzalez Hernandez08 Li
problem Old stars ~ primordial Sbordone et al. (2010) Aoki et al.
(2009) log(Li/H)+12
Slide 7
Weak Interaction Electromagnetic Interaction ee Coulomb
Scattering p n A Strong Interaction The Space expands Gravitational
Interaction 4. Standard BBN (1)
Slide 8
np equilibrium (n/p) EQ =exp(-Q/T) Qm n -m p =1.293MeV t ~
1sec,T=T F ~1MeV(week interaction freeze-out) e + e - n p e (T~m e
/3) (n/p) freeze-out =exp(-Q/T F )~1/6 (1MeV=1.1610 10 K) Kawano
code (1992) Rates: Smith et al. (1993) +Descouvemont et al. (2004)
+JINA REACLIB (Dec., 2014) n =880.3s (Olive et al. [PDG] 2014) n b
/n =6.03710 -10 Planck (Ade et al. 2014) 7 Be 7 Li e - -capture
after recombination T 9 T/(10 9 K) 3 He( , ) 7 Be 3 H( , ) 7 Li 7
Li(p, ) 4 He 4. Standard BBN (2)
Slide 9
Astronomical observations dark Matter, dark energy Need for
beyond the standard model (e.g. sterile, SUSY, or modified gravity)
exotic particles, or exotic equations of motion of Universe Li
problem? 5. Possibilities of exotic particles & modified
gravity Nuclear reactions of exotic atoms and exotic nuclei (Cahn
& Glashow 1981)(Dover et al. 1979) Goal checking effects on
BBN, and deriving constraints on models checking possible
signatures on light element abundances X-X- nuclide A X-nucleus
X0X0 nuclide A X-nucleus X Nuclear reactions triggered by decay
products
Slide 10
I.Effects of modified gravity (Kang & Panotopoulos, 2009)
Small baryon number in the universe, i.e., 610 -10 solution by the
modified gravity Cutoff scaleBaryon current Interaction that
violate the baryon number # of intrinsic degrees of freedom of
baryons (Davoudiasl et al. 2004) f(R) R n with n 0.97 gives the
observed baryon number density (Lambiase & Scarpetta, 2006)
constraint from 4 He abundance (Kang & Panotopoulos, 2009)
Slide 11
Model: f(R) gravity (1) Action Variation with respect to g
Friedmann-Lematre-Robertson-Walker metric Energy-momentum tensor
equations of motion
Results: f(G) gravity (2) When the deviation of expansion rate
from the standard case is small Negative 0
Slide 18
decay life MK, Kajino, Mathews, PRD 74, 023526 (2006) Energetic
is generated photodisintegration of nuclei (Lindley 1979, Ellis et
al. 1985-, Reno & Seckel 1988, Dimopoulos et al. 1988-,
Kawasaki et al. 1988-, Khlopov et al. 1994-, Jedamzik 2000-, MK et
al. 2006-) Decay of X generation of very energetic 7 Be can be
destroyed But other nuclei are simultaneously destroyed 7 Li
problem cannot be solved (Ellis et al. 2005) II.Effects of sterile
neutrino decay
Slide 19
Assumption: exotic particle (X) decays with energy E 0 1.
Primary (1 st ) process disintegrates background nuclei
Interactions with background and e (Cyburt et al. 2003)
Interactions with background and e 2. Secondary (2 nd ) process
Reactions of primary product with background nuclei 6 Li production
(Cyburt et al. 2003) Destruction of d,t, 3 He, 6 Li produced in 1
st processes abundance parameterlife time X AXAX AXAX 1 st 2 nd 3
H(p,dp)n 3 H(p,2np)p 3 He(p,dp)p 3 He(p,2pn)p 2 H(p,pn)p 6 Li(p, 3
He) 4 He MK, Kajino, Mathews, PRD 74, 023526 (2006) 2 H( ,n)p, 3 H(
,n) 2 H, 3 H( ,np)n, 3 He( ,p)d, 3 He( ,np)p, 4 He( ,p)t, 4 He( ,n)
3 He, 4 He( ,d)d, 4 He( ,np)d, 6 Li( ,np) 4 He, 6 Li( ,X) 3 A, 7
Li( ,t) 4 He, 7 Li( ,n) 6 Li, 7 Li( ,2np) 4 He, 7 Be( , 3 He) 4 He,
7 Be( ,p) 6 Li, 7 Be( ,2pn) 4 He Model: nonthermal
nucleosynthesis
Slide 20
7 Li reduction without other effects Solution: 1.59 MeV < E
0 < 2.22 MeV fine tuned photon energy 7 Be( , ) 3 He MK,
Balantekin, Kajino, Pehlivan, PRD 87, 085045 (2013) Nucleithreshold
(MeV) Reaction 7 Be1.587 7 Be( , ) 3 He D2.225 2 H( , n) 1 H 7
Li2.467 7 Li( , t) 4 He 3 He5.494 3 He( , p) 2 H 3H3H6.527 3 H( ,
n) 2 H 4 He19.814 4 He( , p) 3 H [assumption] thermal freezeout
abundance of weakly interacting massive particles Results:
radiative decay (1)
Slide 21
best region MK, Balantekin, Kajino, Pehlivan, PRD 87, 085045
(2013) Constraint on the mass, life time, & magnetic moment of
sterile s l + Results: radiative decay (2)
Slide 22
Lagrangian Dirac sterile neutrino, mass M H =O(10) MeV,
active-sterile mixing