1 / 8

Plan of my talk Littlest Higgs Model with T-parity Relic abundance of LTP dark matter

Dark matter in the little Higgs model ~ Indirect detection of LTP (Lightest T-odd Particle) dark matter using cosmic positron measurement ~. Collaborated with Masaki Asano (KEK) Nobuchika Okada (KEK) Yasuhiro Okada (KEK). Shigeki Matsumoto (KEK, Theory).

tuan
Download Presentation

Plan of my talk Littlest Higgs Model with T-parity Relic abundance of LTP dark matter

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dark matter in the little Higgs model~ Indirect detection of LTP (Lightest T-odd Particle) dark matter using cosmic positron measurement ~ Collaborated with Masaki Asano (KEK) Nobuchika Okada (KEK) Yasuhiro Okada (KEK) Shigeki Matsumoto (KEK, Theory) • Plan of my talk • Littlest Higgs Model with T-parity • Relic abundance of LTP dark matter • 3. Cosmic positron signature from LTP annihilation

  2. New-Phys.(10TeV) & EW(0.1TeV) 1. Higgs field = pseudo NG boson 2. Special arrangement for the cancellation of Λ2 at 1-loop. ① Little Higgs scenario Arkani-Hamed, Cohen, Katz and Nelson (2002) SU(5)⊃[SU(2)×U(1)]2(gauged) ② Littlest Higgs Model (LHM) (VEV = f ~ O(1) TeV) SO(5)⊃SU(2)×U(1) (diagonal) ③ Higgs potential Based on non-linear σ-model (Σ=e2iΠ/fΣ0) generated radiatively through the Colman-Weinberg potential e.g) W WH Dμ: (B1, W1 ; B2, W2) (g1, g’1 ; g2, g’2) Heavy & SM Gauge bosons h h h h – g2 g2 V(φ) = －μ2φ2 + λφ4 Σ：(24 – 10) pions Triplet Higgs 1-loop log Λ 2-loop Λ2 1-loop log Λ eaten SM Higgs under SM gauge group

  3. Spectrum 10 (T-even) (T-odd) Φ WH , ZH 1 (TeV) h AH W, Z 0.1 impose T - parity B1(W1) ⇔ B2(W2) Π⇔－ΩΠΩ Ω= diag.(1,1,–1,1,1) (no heavy gauge boson exchange, no triplet VEV.) ④ LHM with T-parity Original LHM is suffered from severe constraints from EWPM. (Tree-level corrections due to the exchange of additional heavy gauge bosons and non-vanishing VEV of triplet higgs.) f must be larger than 5 TeV !!  fine-tuning again Constraint from EWPO (S,T,U) Sample point Lightest T-odd Particle (LTP) is stable  Good Candidate of Cold Dark Matter !! Hubisz, Meade, Noble, Perelstein (2005)

  4. Relic abundance of LTP dark matter Dominant contribution to Calculation of Relic Abundance ( If mAH > mh ) Relic abundance of the dark matter can be explained by LTP naturally in the usual thermal relic scenario. Ωｈ２= 0.111 ± 0.006 Signatures of LTP dark matter in indirect detection measurement using e+. Sample point 0.8

  5. Annihilate 1~2 kpc e+ e+ Sun Halo LTP dark matter annihilates into e+ in the galactic halo Indirect detection of LTP using e+ LTP dark matter annihilation Astrophysical ambiguity on the signal (and background) is small compared to other indirect detections. (20 ~ 30 %) e+ do not travel in straight line, the signal is observed as the Positron excess in cosmic rays. e+ is absorbed and loses its energy by the propagation in ISM. The flux at earth mostly originates within a few kpc. N-body simulation suggest the possibility to enhance the signal due to the inhomogeneity in the local DM dist. ( parameterized as BF = ratio of signal with inhomogeneity and without one. The factor may reach 2 ~ 10. )

  6. Possibility to detect the signal in PAMELA Not only DM ann. but also C.R. produces high-energy e+ PAMELA (satellite-borne exp.) e+ : 50 (MeV) ~ 270 (GeV) acceptance : 20.5cm2sr energy res. : 12%/E1/2 + 2% contamination : 10-4 level Background positrons C.R. (primary e-)  secondary e+ during propagation in Galaxy 0.20 PAMELA covers the interesting range of LTP dark matter. To detect the signal, the B.G. estimation is important. positron fraction e+/(e+ + e– ) HEAT PAMELA (expected) 0.10 B.G. will be measure accurately at PAMELA (at 1 ~ 5 GeV) and astrophysical ambiguity will be very small !! 0.05 Background (GeV) 0.01 The LTP dark matter signal can be detected at the range ~ 100 GeV. 1 10 5 50 100

  7. Positron Signature from LTP DM Deviation from B.G. Energy bins of width Δ(log E) = 0.60 (E < 40 GeV) Δ(log E) = 0.64 (E > 40 GeV) χ2/d.o.f. = 2.11 > 95% C.L. ( = 1.3) Positron Fraction : e+/(e+ + e– ) 0.024 PAMELA f = 1.4 TeV mh = 340 GeV m = 220 GeV (sample point) bins 0.020 Signal + B.G. Background 0.016 BF = 5 Hooper & Silk (2004) 50 100 200 500 E (GeV) PAMERA may be capable of observing the LTP dark matter. (AMS-02, the sensitivity is improved, can detect the signature even if BF = 1)

  8. Summary • We investigate the possibility to detect the signature of the LTP dark matter in indirect detection using positrons. • PAMER can distinguish the signature from B.G. if BF = 5. • AMS-02, the sensitivity is considerably improved, can detect the signature even if BF = 1. Future directions • Constraint the LHMwT from direct detection of LTP dark matter • Gamma-ray signature from G.C. • Anti-proton excess in C.R. and neutrino flux from the Sun.

More Related