PoS(DSU 2012)044 http://pos.sissa.it/ ce. d. In addition, staus can only de- s splitting between the te into a stau pair. Since in some echanisms behind this phenomenon massive black hole at the galactic cen- rimentales, Universidad de , ive Commons Attribution-NonCommercial-ShareAlike Licen † ∗ [email protected] Speaker. MultiDark fellow. may be gravitationally boosted near theter super- so that they can have enough collision energy to annihila phenomenologically favored supersymmetric models theand mas the lightest stau is a few GeVs, this channel may be allowe cay into a tau lepton and anotherand neutralino. the We discuss gamma-ray the spectrum m and flux generated by the tau pair. ∗ † Copyright owned by the author(s) under the terms of the Creat c Mirco Cannoni Gamma rays from gravitationally boosted neutralinos at the galactic center

Departamento de Física Aplicada, Facultad deHuelva, Ciencias 21071 Expe Huelva, Spain E-mail: June 10-15, 2012 Rio de Janeiro, Brazil VIII International Workshop on the Dark Side of the Universe PoS(DSU 2012)044 6 7 n − 10 10 × × 5 4 67 pc the = . 1 2, up to the = sp / 2 Mirco Cannoni ρ = 3 c / h ike. Finally, the = r BH sp egion is not charac- γ , GM sp , with 2 γ h is the annihilation cross − r ) = is formed by 0 2 . In this way, for example, . ) sp S S v 0 r is found by matching the two R R / σ Einasto profile, 4 a r ≈ ( 125 GeV [2] and a decay width r rained minimal supersymmetric ( e Jeans equation, the root mean ut unification conditions. In fact > . sp sp a region of the MSSM parameter f r r e correct dark matter relic density, ρ t ominated by a super-massive black on at the GC cannot be resolved by o causes a steepening, called spike, nce, new annihilation channels into 0 ilation channel is opened already for ng of DM particles off stars, capture e BH can originate very high energy ) must be inferred by physical consider- v )= g the evolution of the DM distribution, , it is argued that in the innermost region y in the bulge of the [13] should σ r ( ( would cross the horizon if the pericenter / her rising reaching a constant value, com- ρ tic particles, could be accessible. χ c . The radius L m S R = a 2 ρ [14, 9, 10], or in terms of the Schwarzschild radius, and Schwarzschild radius 2 / ⊙ 22 and sub-relativistic velocities are possible. . 1 ) 0 M r 6 , a mild spike (MS). To this picture the adiabatic compressio / 2 ≃ [8 – 12]. At a certain distance from the GC the density reaches / . are light and degenerate [3]. 10 1 BH sp 2 1 2, up to the limit 4 − γ 20 ˜ / × , hence we will consider safely τ / r / 3 S 1 4 √ 1 − GM − ∝ R / r ( ) 4 1 = = ) r sp ∝ a ≈ ( = ≃ γ ρ ) BH , / ) r c ms a a r ( / M γ ρ ( min ρ v sp . Since a Keplerian orbit with − r v ( ) 2 ρ , is almost degenerate in mass with the neutralino [1]. This r a / sp 1 1 r r 10 Gyr [11, 8] is the elapsed time since the formation of the sp ˜ ) τ / r r = = 2 ( a a / f r ρ we have S t R S as in [11]. From here the profile is given by ( where the density reaches the value R 3 a ≈ r 10 c Given a density described a power-law distribution, from th In one the favored regions of the parameter space of the const The gravitational potential in the galactic center (GC) is d We hence model the profile considering that at the radius The dark matter density distribution in the sub-parsec regi We briefly discuss here the mechanism proposed in Ref. [5]: if = / ) r r ( distance is less than teristic of the CMSSM only, butthe also recent of evidence the at general LHC MSSM ofinto witho the two Higgs photons boson larger with mass thespace where around in the the neutralino and Standard Model, single out at squared velocity is GeV/cm standard model (CMSSM) where thethe lightest lightest stau, neutralino has th radius Gamma rays from gravitationally boosted neutralinos 1. Introduction hole (BH) with mass section and v monly called annihilation plateau or core.the In [12], density however behave as a value such that self-annihilation itself acts to stop furt also be added. of the gravitational potential caused by the baryons alread pc. It has beencollision suggested in in [4] the that center particles ofheavier captured mass states, by kinematically frame th forbidden (CMF). for In non relativis principle, he neutralinos with the above properties,sub-relativistic a neutralinos new [6] dominant not annih captured by the BH. 1.1 Dark matter density profile at the GC present simulations nor by rotation curvesations. measurement but The adiabatic growth ofof the the BH initial at halo the center profileby of toward the the the BH, hal GC self-annihilation [7]. andresults Adding capture in scatteri within a stars profile, durin power-laws, influence radius of the BH, DM density is given by a compressed inner MS is PoS(DSU 2012)044 , t − 26 ˜ − τ m 10 × = ( otons but is approxi- ity is, thus, δ ) , τ 2 1 Mirco Cannoni ˜ τ m 197: there exists . − 0 χ p ≥ nihilation. · c ˜ τ re thus the ones with / − + r stau pair production is p v τ τ 2 0 1 0 1 χ χ . The CMSSM points A and + s ˜ 2%, τ ilation channel is twofold. The √ E = χ − + an the freeze-out value 3 splitting with the ntal errors. The cross section for ) are suppressed, while the vertex τ τ E δ 0 1 0 1 22 GeV and are compatible with a 2 he threshold the produced staus are mass, the staus can only decay into H o reach the threshold of the process 1 the annihilation cross section times χ χ 1 , ˜ τ ¯ ˜ τ − h ty of colliding neutralinos. Note that by one or two orders of magnitude the χ 2 –( m . With χ 2 – / 1 + 1 ¯ 1 ˜ χ τ ˜ ˜ τ ] 2 τ 2 m ) 0 1 ( 0 1 2 that are just the ones that can be obtained with δ and . χ / χ 3 0 + − 1 + Z τ τ 0 1 0 1 – − 1 = χ χ ( Z,h,H χ 1 . τ 2 / – 0 1 m χ − ∼ − 1 c 2 [ ) / 1 ˜ ¯ τ v 1 ˜ τ ≥ ˜ 0 1 0 1 τ p χ χ c τ τ / − v χ 2 p . The cross section, proportional to the square of this quant ( ] / , see diagrams in Fig. 1. The tau pair will decay and radiate ph 2 τ m 0 1 0 1 χτ χ χ − Diagrams for stau pair production and decay in neutralino an 2 ) χ , that implies m ˜ τ − m ˜ τ 2 . Figure 1: m + ≥ ˜ [( τ χ / , is typically less than 5%. In the CMF the energy threshold fo is not suppressed by mixing. The dominant diagrams in Fig. 1 a − E ˜ χ τ τ 2 near the threshold is at least an order of magnitude bigger th m – If the neutralino-stau mass splitting is larger than the tau In Fig. 2, we show the relevant cross sections as a function of The relic density constraint implies that the relative mass The reason why the stau pair production is the dominant annih / /s. These values corresponds to 1 → = ˜ ) 3 rel τ s channel exchange of the tau. Furthermore, at energies near t χ v – χ χχ 3. Gamma rays from non-monochromatic taus enhanced for mass splittings approaching the tau mass. the two body final state u slow thus the propagator 1 thus a range of radii where the kinetic energy is high enough t σ Gamma rays from gravitationally boosted neutralinos 2. Large annihilation cross section into a stau pair with a peculiar spectrum. B, see Ref. [5] forHiggs details, of predict mass a 125 Higgs GeVstau mass within pair-production around the near 119-1 theoretical the and threshold thecross clearly experime sections dominates for annihilation.the In particle the relative right velocity, panels as we a show function the CMF veloci m √ mately 1 cm neutralino is bino-like thus the vertices’s the gravitational boost discussed above. PoS(DSU 2012)044 2 4 = ≃ / 1 ) and ) → (3.1) s dx s / / τχ ˜ τ 2 γ √ m → ators, and 4 dN 1 ˜ . − τ ) ( Mirco Cannoni 1 τ ∗ ns is shown in . This formula 2 x p / β BR = ( ) ) 2 1 + β ˜ τ his frame it has fixed ∗ + τ is given by /s) 1 . The resulting energy ˜ x 3 E τ τ 2 ( 2 / E 1 γ ) → − 2 τ = 2 . The taus energy spectrum the collision energy x m (cm χ v/c χχ m ( − )]( max τ x 2 σ rel E = ∗ τ − τ v E CMF energy (left panels) and annihila- ≃ ≤ 1 ails, by fitting the photon yield from =333.6 GeV E =789 GeV with parameters =327.2 GeV energy distribution of the full 2 σ =782.2 GeV τ ) τ ( neutralino and stau masses are given. χ χ τ m p = ( E m m m = [ A B τ ∗ χχ us have an energy equal to the neutralino ≤ p + log ) max γ τ ∗ τ q E − 0.001 0.01 0.1 1 0.001 0.01 0.1 1 p -24 -24 -25 -25 -28 -29 -30 -28 -29 -30 -27 -27 -26 -26 and τ β ˜ τ )]+ 10 10 10 10 10 10 10 10 10 10 10 10 10 10 , − → x m 4 ( ∗ τ 2 /s as a function of the colliding neutralino velocity (right g min τ / E [ 3 ) χχ ( E 2 τ ( A B γ produced by a tau with energy − m exp σ γ = R 2 + E l / + τ R 3 max τ − l χ 2 ~~ − min τ τ E x m E = ) − + ˜ τ 2 , )= E 1 x µ bb (pb) m ~ τ E ∆ ( (GeV) 1, we have 1 − 1 f ∆ σ τ ~ µ 4, applying the small width approximation to the stau propag ( = ( = 1/2 + )= ∗ τ → e and ) χ s E − [15]. τ An example of the accuracy of these analytical approximatio ± e χτ E . τ ˜ τ / ˜ τ τ γ → → σ E 1 , to the spectrum calculated in the rest frame of the stau. In t 1 1 dE 2 2 0 0 600 800 1000 1200 ˜ ± ˜ τ 1 τ -1 -1 ≡ 1500 1600 1700 1800 -3 -2 -2 = ˜ ( τ ) m ( x 10 10 10 10 10 10 CalcHEP 1 2 10 10 10 10 10 ˜ dN τ / BR 1 s ˜ τ Annihilation cross sections in picobarn as a function of the with √ ) → x = ( The number of photons with energy The taus are not monochromatic and the spectrum changes with γ f χχ 2 ( / process with given that energy and momentum, panels). The CMSSM points A and B are specified in Ref. [5], the tion cross section times the relative velocity in cm and 1 Although the process is 2 σ Figure 2: Gamma rays from gravitationally boosted neutralinos Fig. 3(a) where the histogram is obtained by calculating the was obtained in Ref. [16], to which we refer the reader for det can be easily obtained by applying a Lorentz transformation ultimately with the distance, while inmass the and static case the the radiated ta photon spectrum is limited by distribution is flat and limited, PoS(DSU 2012)044 min τ E (3.2) (4.1) nd (d) . In this − τ + Mirco Cannoni MicrOMEGAs τ → χχ 0 0 . ) 10 10 . γ ) (b) (c) E pairs with energy of the lepton r 8 kpc. The differential photon ( − γ − -1 -1 τ = τ τ 10 10 dN + viside function takes into account dE /E E D γ τ ( ) f vistic process r θ χ =5 GeV 2 =10 GeV ( τ x=E τ -2 -2 2  E m E ectrum as given in the code 10 10 γ τ ρ 2 for the yield of one particle. Although ) γ E E γ / r nel (c) the red line is the tau spectrum, and the (  dN dx dN dx -3 -3 f rel 1 1 0 0 2 2 10 10 v -1 -1 τ -2 -3 -2 -3 τ ) 10 10 10 10 10 10 r 10 10 10 10 10 10 E [17], see Fig. 3(b), Fig. 3(c). 1 ( dE 5 . For this reason the photon energy cut-off is ˜ ) τ 10 τ r ˜ τ ) ( r that is too small to be resolved by present telescopes, E σ ( (a) (d) 2 Z 0 max τ > min τ E 10 max E γ r drr ) is then obtained by integrating over the tau energy distri- E r r ( max -1 6 8 10 1 r Z min r E 10 684 GeV. 2 (GeV) (GeV) 3 S . Panel (d) shows the convoluted gamma-ray spectrum. In (c) a 25 GeV, it works well also down to few GeV by confronting it ∆ γ τ τ E R E D σ = MicrOMEGAs γ -2 d 4 ≥ E dE s 1 1 ∆ 10 σ τ = )= dN' dE √ r E γ ( Φ -3 2 γ = d 1 2 0 0 dE CalcHEP 10 -1 -1 -4 -2 -3 -5 dN dE 10 10 10 10 10 10 10 10 10 10 DM m the integrand is zero if γ E , see Fig. 3(d) for an example. s Panels (a) and (b) show the photon spectrum emitted by √ The extension of the source is set by The gamma spectrum at distance flux as thus we treat it as point source at the GC at a distance from us o 4. Flux taus obtained with Monte Carlo simulations of the non relati for each Figure 3: Gamma rays from gravitationally boosted neutralinos case the taus have equal energy,the hence fit we is use obtained a for factor 1 histogram is calculated with fixed to 5 and 10 GeV. Theand points the correspond line to is the the simulated the sp fit function discussed in the text. In pa bution, we use the CMSSM point A and We have multiplied by 2 tothat obtain for the fixed yield of the pair. The Hea with spectra as given in tables of PoS(DSU 2012)044 . r S / R ∗ τ ] is at , 181 2 E ) s ˜ 13 τ √ m / ˜ nd C. Pallis, χ 1 and m Mirco Cannoni ( ∼ ) − is dimensionless 1 r [ max 2 r for energies between ( / γ 1 1 , Astropart. Phys. − = A B s the neutralino; the signal, 2 der-Ingenio 2010 Program. en integrating over − max served by the collaboration. r . Note that 3781 and from the Grant MICINN- ameter space ∗ τ hild radius, thus ctor 1/2 in he flux because the final ter 5 years operation, the Fermi-LAT E his work is supported by a MultiDark ) ark matter particles is not changed by e factors in the integrand depend on ´ erez-Garcia and J. D. Vergados for col- photons cm annihilation there is no factorization into max r 11 ( − − γ τ Calculations of neutralino-stau coannihilation (GeV) + 10 τ → γ × E 6 5 → . min τ 0 E χχ − ´ omez, Angeles P 10 − 0 and → β , , 413 (2001)]; [hep-ph/9905481].M. E. Gomez, G. Lazarides a max 0.1 1 10 r 15 -11 -14 -12 -13 -10

Differential flux for the two CMSSM reference points A and B. 10

10 10 10 10

→

γ γ

(GeV cm (GeV dE d s ) E r Φ/

2 -2 -1 appears explicitly. The maximum radius is given by Figure 4: 3 S R , thus the cut off is indicative of the mass splitting between . In fact as ) ∗ τ χ E m ) channels and the cosmologically relevant region of MSSM par (2000), [Erratum-ibid. In Fig. 4 we show the differential flux. The absolute cut off wh It is a pleasure to thank Mario E. G − max ˜ τ [1] J. R. Ellis, T. Falk, K. A. Olive and M. Srednicki, r ( m a particle physics and an astrophysics factor because all th through the velocity dependence.state Furthermore necessarily there contains is two no neutralinos,this fa the process. number of d γ In the integral distances are given in units of the Schwarzsc Gamma rays from gravitationally boosted neutralinos In contrast with the standard almost-static ( then, shows up at energies below 10satellite GeV. It [18] is reaches expected that sensitivities af of 10 and a factor under Grant No.Further CSD2009-00064 support is of provided the by the SpanishINFN(PG21)AIC-D-2011-0724. MICINN project MICINN FPA2011-2 Consoli References laboration in Ref. [5] on which this presentation is based. T 0.5 GeV and 10 GeV and the signal can be one of theAcknowledgments components ob PoS(DSU 2012)044 , , gh , , , , etric 76 93 20 92 77 , 1719 Photon 83 Mirco Cannoni , Phys. Rev. D , Phys. Rev. D ]. , Phys. Rev. Lett. , 123512 (2000) , 1 (2012) [1207.7214]; 001.3706]. , 115015 (2012) cusp , Phys. Rev. Lett. , Comput. Phys. Commun. 61 , Mod. Phys. Lett. A 85 716 , Phys. Rev. Lett. nter New gamma ray signal from dos, . Lineros and A. L. Maroto, Contraction of Dark Matter Galactic , Dark matter dynamics in Galactic center , Phys. Rev. D , Phys. Rev. D , Phys. Lett. B r y.sinp.msu.ru/ pukhov/calchep.html. Particle Dark Matter: Observations, Models , 30 (2012) [1207.7235]. , 083507 (2011) [1009.4936]. , in , 147 (2011). , 27 (1986); F. Prada, A. Klypin, J. Flix Molina, 83 716 , Princeton University Press, Princeton, NJ, 1987. 7 630 301 Search for dark matter with Fermi Large Area Telescope: , 241301 (2004) [astro-ph/0401512]. Y. Mambrini, Observation of a new boson at a mass of 125 GeV with Correlation between the Higgs Decay Rate to Two Photons 93 Observation of a new particle in the search for the Standard Kerr Black Holes as Particle Accelerators to Arbitrarily Hi Adiabatic compression and indirect detection of supersymm Dark Matter Profile in the Galactic Center , Phys. Rev. D Dark Matter Annihilation in the Milky Way Galaxy: Effects of (2012) 186 [1207.6393]. , Phys. Lett. B Relativistic dark matter at the Galactic center , Astrophys. J. , 111102 (2009) [0909.0169]. Galactic Dynamics Dark matter dynamics and indirect detection 1210 103 Dark matter annihilation at the galactic center , Phys. Rev. Lett. [CMS Collaboration], Indirect search for dark matter with micrOMEGAs2.4 , Nucl. Instrum. Meth. A , JHEP , , 083506 (2008) [0803.0002]. [Fermi-LAT Collaboration], et al. 78 [ATLAS Collaboration], , edited by G. Bertone, Cambridge University Press (2010) [1 et al. Dark matter annihilation near a black hole: Plateau vs. weak , J. Cosmol. Astropart. Phys. 01 (2006) 010 [hep-ph/0506204 Dark matter at the centres of Evolution of the dark matter distribution at the galactic ce et al. et al. , Phys. Rev. Lett. , 842 (2011) [1004.1092]. [hep-ph/9907261]. Model Higgs boson with the ATLAS detector at the LHC Supersymmetric with Yukawa unification S. Chatrchyan the CMS experiment at the LHC 1021 (2005) [astro-ph/0504422]. andthe Muong - 2 201304 (2004) [astro-ph/0311594]. 103532 (2007) [0707.3334]; E. Vasiliev andPhys. M. Rev. Zelnikov, D (1999) [astro-ph/9906391]. C. Munoz, E. Nezri and F. Prada, Halos Due to Baryonic Infall Energy 123510 (2008) [0710.5517]. and Searches [1205.1709]. spectra from WIMP annihilation gravitationally boosted neutralinos at the galactic cente M. Martinez and E. Simonneau, Baryonic Compression 182 The galactic center 061302 (2004) [astro-ph/0308385]. dark matter [2] G.Aad [8] D. Merritt, [3] G. F. Giudice, P. Paradisi and A. Strumia [7] P. Gondolo and J. Silk, [6] M. A. Amin and T. Wizansky, [4] M. Banados, J. Silk and S. M. West, [5] M. Cannoni, M. E. Gomez, M. A. Perez-Garcia and J. D. Verga [9] O. Y. Gnedin and J. R. Primack, [12] E. Vasiliev, [17] G. Belanger [11] G. Bertone and D. Merritt, [13] G. R. Blumenthal, S. M. Faber, R. Flores and J. R. Primack [18] V. Vitale [10] D. Merritt, [15] A. Pukhov, A. Belyaev and N.[16] Christensen, http://theor J. A. R. Cembranos, A. de la Cruz-Dombriz, A. Dobado, R. A [14] J. Binney and S. Tremaine, Gamma rays from gravitationally boosted neutralinos