astroparticle physics with ams-02

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Astroparticle Physics with AMS-02

Dr. C.SbarraINFN-Bologna, Italy

On behalf of the AMS collaboration

12th Lomonosov Conference, Moscow 2005

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Outlook

The AMS experiment and its forthcoming operation on International Space Station (ISS)

The antimatter discovery potential of AMS-02 and the Baryogenesis scenarios investigated

The e+ , p , d detection and subsequent impact on the various models of exotic physics

Dr.C.Sbarra, INFN-Bologna, Italy 12th Lomonosov Conference, Moscow 2005

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The Test Experiment: AMS-01


Results: • Environmental studies• Background studies• Fulfill the constraints from space• Antimatter/matter limit (<1.1x10-6 at 95% C.L. PR 366/6, 2002)

Onboard the shuttle Discovery Onboard the shuttle Discovery (1998)(1998)

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The AMS-02 experiment


The knowledge obtained in the precursor 10 days flight AMS-01 (1998) was used to redesign the spectrometer for the ISS:

Long exposure: > 3 years Superconducting magnet

(BL2 0.86 T, 1m3 fill volume)

Large acceptance: 0.5 m2 sr Many repeated measurements

of particle velocity, momentum and charge

The Anti Matter The Anti Matter SpectrometerSpectrometer

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ISS at 400 km of altitude-excellent geomagnetic and galactic coverage- about 16 revolution/day-51.57° orbit inclination-precession 5°/day

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Huge statistics of all type of Cosmic rays in the energy range 1 GeV – 1 TeV (/nucl)

For low rates high redundancy and precise detector measurements

The AMS-02 experimentPID : The PID : The subdetectorssubdetectors

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You will ear by Divic Rapin about the many constraints due to operation in space

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20 layers of TRD for e+/h sep. (1.5 -300 GeV)

4 layers of TOF for trigger, time (150 ps), β and |Q| meas.

8 layers of double sided Silicon tracker for p (10/30 μm res. b./non b.) and ±Q meas.

VETO Counters RICH for β (Δβ/β~0.1%) and |Q| 3D sampling ECAL (17X0of

plastic fibers) for e+e-/h sep. (1.5 GeV-500GeV)


PID : The PID : The subdetectorssubdetectors

Super conducting Solenoid (0.86 T)

He vessels

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- few matter traversed by charged particles-TRD and RICH can give the velocities for high energy particles; the TOF only for low energy particles.e/p rejection: -TRD (measures gamma lorentz trough transition radiation emitted passing interfaces. At high energy positron will radiate, proton will not); -ECAL (measures shower profile, recognizes electron by proton by shower shaping - imaging)-TOF/RICH velocity measurements for e/p rej. at low energies

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-TRD: Rej=10^2-10^3- Ecal : Rej = 10^4<3% energy res. above 10 GeV, gamma detection standalone trigger- Rich: 0.1% beta precision , charge separation, isotope separation, 2% precision on mass below 10 GeV/n- Tof: few percent beta precision

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The AMS-02 experimentSpectrometer Resolution (P.R. Spectrometer Resolution (P.R. 366/6)366/6)


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A basse energie:He ha risoluzione peggiore per colpa del multiple cattering: theta_m prop. z^2/(p*beta) prop. M/R^2quindi a stessa rigidità l'He ha angolo maggiore che peggiora la rislz.A alte energie:A parità di rigidità l'He è più lento del protone....(però non so bene come consegue che la risoluzione è peggiore per p..)

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The physical laws at microscopic level are symmetric between baryons and anti-baryons

The physical Universe seems to be asymmetric (there seems to be only matter)

- How can evolve an asymmetric universe (totally or even only locally) from a primordial big-bang and with symmetric laws? baryogenesis ? baryogenesis ?


The AMS discovery potential Antimatter in our Antimatter in our universeuniverse

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Andrei Shakarov put the necessary conditions for baryogenesis [JETP Lett. 91B,24 (1967)] :

Baryon number B non conservation C and CP non conservation Out of equilibrium decay- The inflation is a natural scenario where a baryogenesis can

take place: it allows the out of equilibrium condition and it can avoid the a-prori hypothesis of initial symmetric conditions [L.F. Abbott et Al.,Physics Lett.117B(1982)]

Antimatter in our universe: Antimatter in our universe: BaryogenesisBaryogenesis


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Is the Universe globally or only locally asymmetric? In a totally symmetric universe, high energy CRs

could escape from an antimatter domain and get to our galaxy

On the basis of γ-rays observations our matter dominated region has at least the size of cluster of galaxies

Is there place for antimatter in a totally asymmetric Universe as seem to be ours?



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Cluster of galaxies scale: 1-10 Mpc

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[M. Y. Khlopov, S.G.Rubin and Al.S.Sakharov hep-ph/0210012 ] In the matter dominated universe there is also the

possibility of small insertions of antimatter regions :Quantum fluctuations of a complex, baryonic charged

scalar field caused by inflation can generate antimatter regions that can survive annihilation

There can exist antistar global clusters in our galaxy The expected signature of such scenario is a flux of

3He and 4He accessible to AMS-02



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Antimatter regions left from baryogenesis can evolve into condensed antimatter object, footprints of early phase transitions (far above ew energies).The evolution of this antimatter regions could cause every galaxy to be a harbor of an anti-star globular cluster (GC). The existence of GC is not in contraddiction with the observed CMB and the flux of antinuclei from it can be observed by AMS-02 (but could not by AMS-01)

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An anti-nucleus can be found in Cosmic Rays, with a spectrometer on top of the atmosphere (balloons) or on a satellite (Pamela, AMS-02)

Antimatter in our universe: Antimatter in our universe: Experimental searchesExperimental searches

Pamela


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if an anti-nucleus is sympthetized in an anti-star , and, if the acceleration mechanisms are the same that in a star, then some anti-nuclei can reach the hearth, provided enough energy to overcome the galactic windthere could be also globular clusters of anti-satrs in our own galaxy [Alexander Shakarov, hep-ph/0210012] -BESS ha il miglior limite (Sasaki et al.)

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Antimatter in our universe: Antimatter in our universe: Antinuclei, antiparticlesAntinuclei, antiparticles

The antiparticles are “secondaries” produced by CR interactions with ISM through inelastic collisions – “spallation”Flux 4He O(10-12), D O(10-8), p O(10-4), e+ O(10-3)

But some antiparticles can be “primaries” from exotic sources of antimatter or DM annihilation(an He would be evidence of antistars)


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Ratio e+/(e++e-) can reveal neutralino annihilations [Phys.Rev.D 65/6]

HEAT data HEAT data show possible show possible excess around excess around ~~10GeV 10GeV

Antimatter in our universe: Antimatter in our universe: antiparticles - Positronsantiparticles - Positrons

Edsjö et al


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AMS can measure 101066 positrons up to 300 GeV and can confirm or not the bump

Flux ratio : p/e+ ~ 103

Strong p/e+ rejectionStrong p/e+ rejection - TRD : Rej TRD : Rej~10~1033/10/1022 in 3-300 GeV in 3-300 GeV

- ECAL: RejECAL: Rej~~101044 for E for E~~500 GeV500 GeV (TRD + ECAL together Rej (TRD + ECAL together Rej ≥ ≥ 101055))

Antimatter in our universe: Antimatter in our universe: antiparticles - Positronsantiparticles - Positrons


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Antideuteron is to be observed in CRs D limit from Bess < 1.9x10-4 (m2 ·s·sr·GeV/n) [28th ICRC 2003]The neutralino (the lightest supersymmetric The neutralino (the lightest supersymmetric

particle) would be left as relic by large particle) would be left as relic by large amount of sparticles decayedamount of sparticles decayed

AMS-02 can observe O(10) low momentum D from neutralino annihilation [F.Donato et Al.1999]

Antimatter in our universe: Antimatter in our universe: AntideuteronsAntideuterons


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Antideuterio non e' stato osservato in CRs. Mentre il deuterio si (e anche da ams-01), per l'antideuterio ancora non ci sono osservazioni.produzione-spallazione:p+ISM->antid+X (efficace se momento(p)>17GeV e quindi momento(antid)>2GeV)p+O2,N2(upper atm)->antipr,antid + X (non efficace per antid visti da ams02)self annih. of neutralino->antip,antid (efficace per bassi momenti dove la spallazione antid e' soppressa mentre antip e' oscurato dalla spallazione antip )

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The known ratio of D/p is ~ 10-5 in the observed universe

AMS-02 can detect D from antimatter domains : D/p ~ 10-5 (AMS-01 observed ~100 p, thus D was unobservable)

The ratio of primordial He to D is ~ The ratio of primordial He to D is ~ 10104 4 and in CR it is about 10 thus any and in CR it is about 10 thus any D from antimatter domain would be D from antimatter domain would be accompaigned by He or paccompaigned by He or p

Antimatter in our universe: Antimatter in our universe: AntideuteronsAntideuterons


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Dato che AMS01 osservo' 100 antip, allora il numero di antid aspettati sarebbe troppo basso

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Antiproton flux O(10-4) at E~1 GeV(e-/p ~ 103 at E ~ 1 GeV strong e-/p rejection at this energy)

Antiprotons in CRs have been detected up to O(10 GeV) and all seem to be compatible with secondary production

Antimatter in our universe: Antimatter in our universe: AntiprotonsAntiprotons


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Simulation of three years of high statistics measurements of antiproton spectrum

AMS-02 will be able to detect antiprotons up to 400GeV

[V.Choutko,Nucl.Phys.B [V.Choutko,Nucl.Phys.B Proc.Suppl.113-2002]Proc.Suppl.113-2002]

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Proton rejection: good control of charge confusion, interaction with the detector and misreconstructed tracks

Electron rejection: use TOF + RICH beta measurements at low energies, TRD and ECAL rejection capability at high energy



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Wolfendale & Stecker hypothesis [19th ICRC proc. p.354]: We know that the mean lifetime of a CR in the

galaxy falls with energy as E-δ with δ~0.7 If antiprotons are produced and accelerated in an

antimatter domain as the protons are in our galaxy The antiproton/proton ratio , at high energies, would

go ~ Eδ with δ ~ 0.7 , the antiprotons being mainly extragalactic and the protons galactic



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Primary hypothesis: p/p E0.7

From Stecker & Wolfendale, 19th ICRC (La Jolla) 1985, OG6.1-8, p354

At energy E>100GeV the experimental data could discriminate between primary and secondary hypothesis



[data from Golden, Buffington, Bogolmolov]

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con delta=0.7 antip possono essere 1% del flusso dei protoni a 500GeV, mentre 50% a 1 TeV-The data on W&S plot are:-Golden (1984)--presente anche nel plot pg 23-Bogolmolov (1979)-Buffington (1981)--presente anche nel plot pg 23

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Most recent data on p/p[by Picozza and Morselli J.Phys.G:

Nucl.Part.Phys.29 (2003)] Superimposed

extragalactic hypothesis, black hole evaporation model, secondary production

More data could discriminate between the various models for

E >10GeV



AMS-01 [V.Choutko]

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Primordial Black Hole (PBH) evaporation:PBH are small hypothetical black holes produced during the early stages of the Big Bang. Upper limits on their mass density have been put with antip, and assuming their mass spectra.PBH evaporates trough Hawking radiation, and antip plus antin jets gets out, with the production of antid also. This antid from PBH evaporation can be seen below 2 GeV (where secondary production is suppressed)

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As other antiparticles, antiprotons at lower energy could reveal neutralino annihilation:

χχ WW,.. e+, p, D, γ… ( Indirect search in several channels ) Flux of products depends on neutralino

density, CRs propagation terms,..



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Signal :

1) M=964 GeV (4200)

2) M=777 GeV (1200)


Ullio (1999)

Antiprotons are particularly sensitive to the physics details of CR propagation (controlled by B/C ratio), particularly at low momentum

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The AMS-02 spectrometer will measure CRs fluxes with high precision for more than three years

AMS-02 will be sensitive to antinuclei up to 100 Mpc of distance

AMS-02 can discriminate between a totally symmetric or an antisymmetric universe also through antiprotons at E >100GeV

AMS-02 will have the sensitivity to detect the products of DM annihilation in our galaxy through positrons, antideuterons and antiprotons at O(GeV) energy

ConclusionConclusion


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-our is a Virgo cluster has the size of 15 Mpc; on it, it is centered our local supercluster of galaxies which has the extent of 100Mpc.

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SLIDES EXTRA

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Thermal range (day/night ΔT~1000 ) Vibration (6.8 G RMS) and G-Forces (17 G, 9 G take off) Weight limitation (7000 kg) Power limitation (2000 W) Vacuum: < 10-10 Torr Radiation ionizing flux ~1000 cm-2s-1

Orbital debris and micrometeorites Must operate without human intervention (Redunduncy)(Redunduncy)


Operation in Space Operation in Space constraintsconstraints

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p/pbar all recent + Ams01

AMS-01

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p/pbar – all recent data

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Energy resolution (from Palomares)

(E)/E ~ 3% for 100 GeV electrons

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The AMS-02 experimentAMS –AMS –γγ : : 2 modes 2 modes detectiondetection

Converted :Detection of the e+e- pair in the

tracker

Calorimeter :Standalone trigger

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The AMS-02 experimentEnergy Resolution ….Energy Resolution ….

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The AMS-02 experimentAngular Resolution (tracker) Angular Resolution (tracker)

astroparticle physics with ams-02

Documents

lomonosov conference

daythe ams

ams collaboration

spacethe ams

ams discovery potential

outlookthe ams experiment

days flight ams

low energy