aldo morselli infn, sezione di roma 2 & università di roma tor vergata 1 report from italy a....

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


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


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)


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


Differential yield for each annihilation channel

WIMP mass=200GeV

total yields

yields not due to 0decay


Differential yield

for b bar

neutralino mass


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.


Indirect Detection through Cosmic Rays


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


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)


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


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

regions with different m in the M1/2 m0 plane



Signal rate from Supersymmetry

governed by supersymmetric parameters

governed by halo distribution

gamma-ray flux from neutralino annihilation


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


Permitted values of J():


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

GLAST Expectation & Susy models

~2 degreesaround thegalactic center


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


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


NContour plots for GLAST

0.1 < < 0.3

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



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




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


the end

aldo morselli infn, sezione di roma 2 & università di roma tor vergata 1 report from italy a....

Documents

common mass

lightest neutralino

annihilation channelwimp

parameters nb

annihilation channel

higgs sector tang b

chargino mass matrices

free parameters