Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 1

Report from Italy

A. Morselli, A. Lionetto, A. Cesarini, F.Fucito, P.Ullio*INFN, Sezione di Roma 2 & Università di Roma Tor Vergata, Italy

* SISSA, Trieste, Italy

GLAST LAT IDT & Collaboration MeetingOctober 22-25, 2002 Goddard Space Flight Center

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 2

Dark Matter and Chandra October 22, 2002 RELEASE: 02-10

Galaxy NGC 720 shows it is enveloped in a slightly flattened, or ellipsoidal cloud of hot gas that has an orientation different from that of the optical image of the galaxy. The flattening is too large to be explained by theories in which stars and gas are assumed to contain most of the mass in the galaxy

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 3

Observational constraints on m and .

A.H. Jaffe et al., Astro-ph 0007333

Bright stars: 0.5% Baryons (total): 4% ± 1% Nonbaryonic dark matter: 29% ± 4% Neutrinos: at least 0.1% (up to 5% ? ) Dark Energy: 66% ± 6%

(Michael S. Turner astro-ph/0207297)

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 4

EGRET data & Susy models

~2 degrees around the galactic center

EGRET data

A.Morselli, A.Lionetto, A.Cesarini, F.Fucito, P.Ullio, 2002

Annihilation channel b-bbarM =50 GeV

background model(Galprop)WIMP annihilation (DarkSusy)Total Contribution

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 5

Differential yield for each annihilation channel

WIMP mass=200GeV

total yields

yields not due to 0decay

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 6

Differential yield

for b bar

neutralino mass

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 7

Indirect Detection through Cosmic Rays

• We compute (using Darksusy) the expected continuum gamma ray flux from a small region around the galactic centre ( 2 degrees) due to neutralino-neutralino annihilations.

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 8

Indirect Detection through Cosmic Rays

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 9

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 10

the method:

•We choose all the values of the parameters (Nb , N) that satisfy the condition

we fixed Nb to the maximum value allowed by the above condition (when N=0)The points indicate the regions where we can discriminate the neutralino signal with GLAST at 5 sigma level in two years.

backgroundneutralino signal

~2 degreesaround thegalactic center

background model(Galprop)

gamma from annihilation(one example from DarkSusy)

EGRET data

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 11

Supersymmetry introduces free parameters:

In the MSSM, with Grand Unification assumptions, the masses and couplings of the SUSY particles as

well as their production cross sections, are entirely described once 5 parameters are fixed:

• M1/2 the mass parameter of supersymmetric partners of gauge fields (gauginos)

• the higgs mixing parameters that appears in the neutralino and chargino mass matrices

• m0 the common mass for scalar fermions at the GUT scale

• A the trilinear coupling in the Higgs sector

• tang = v2 / v1 = <H2> / <H1> the ratio between the two vacuum expectation values of the Higgs fields

(3S)

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 12

LEP Experimental

lower limit on the mass of the

lightest neutralino assuming MSSM

(Minimal Standard Supersymmetric Model)

MGeV

Limits on Supersymmetry already established

hep-ph/0004169

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 13

A. Morselli,A. Lionetto,A. Cesarini, F.Fucito, P.Ullio 2002

regions with different m in the M1/2 m0 plane

A. Morselli,A. Lionetto,A. Cesarini, F.Fucito, P.Ullio 2002

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 14

Signal rate from Supersymmetry

governed by supersymmetric parameters

governed by halo distribution

gamma-ray flux from neutralino annihilation

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 15

From rotation curves

a =core radius of halo

Isothermal profile 2 2 0 =0 no cusp

Navarro-Frenk-White 1 3 1

Moore et al… 1.5 3 1.5

Kravtsov et al.(a) 2 3 0.2 Kravtsov et al.(b) 2 3 0.4

/)())/(1()/(

)()(

arar

rr c

Halo distributions

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 16

Permitted values of J():

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 17

A.Morselli, A.Lionetto, A.Cesarini, F.Fucito, P.Ullio, 2002

GLAST Expectation & Susy models

~2 degreesaround thegalactic center

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 18

effective area distribution of observing time with inclination angle for the declination of the Galactic center. This is for a sky survey with +/-35 deg rocking and with the inclusion of the loss of exposure due to SAA (South Atlantic Anomaly) passages. The target direction was considered to be viewable if its zenith angle was no more than 105 deg. The fractions are for one precession period of the orbit (54.9 days). The main numbers are :Fraction of time in SAA: 0.142 Fraction of non-SAA time that source is not occulted: 0.592 Net fraction of time that source can be observed: 0.508 The figure divides this fraction into inclination angle ranges, the sum of all values is 1

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 19

Relative Effective Area

Aeff(theta) (relative to the effective area at theta=0) in function of the angle from the zenith of the apparatus, for two cases, one simplified (Aeff(theta)= 1- (theta/66)^2) and the Aeff found in the Montecarlo Study for the Proposal, shown in red , with a more complicated parametrization, the simplest I found is:Aeff(theta) =0.99531+0.00227* theta -0.00035684* theta ^2 +2.345/1000000* theta ^3

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Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 21

NContour plots for GLAST

0.1 < < 0.3

Excluded by LEP chargino mass limit > 95 GeVor because the neutralino is not the LSP

A. Morselli,A. Lionetto,A. Cesarini, F.Fucito, P.Ullio 2002

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 22

NContour plots for GLAST

0.1 < < 0.3

Excluded by LEP chargino mass limit > 95 GeV or or because the neutralino is not the LSP

A. Morselli,A. Lionetto,A. Cesarini, F.Fucito, P.Ullio 2002

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 23

A. Morselli,A. Lionetto,A. Cesarini, F.Fucito, P.Ullio 2002

NContour plots for EGRET

0.1 < < 0.3

Excluded by LEP chargino mass limit > 95 GeV or or because the neutralino is not the LSP

Aldo Morselli INFN, Sezione di Roma 2 & Università di Roma Tor Vergata 24

the end