Bound-free pair production in heavy-ion collisions at high energies - - PowerPoint PPT Presentation

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Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest Bound-free pair production in heavy-ion collisions at high energies Rainer Schicker Phys. Inst., Heidelberg Juni 19, 2015

SLIDE 1

Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest

Bound-free pair production in heavy-ion collisions at high energies

Rainer Schicker

Phys. Inst., Heidelberg

Juni 19, 2015

Rainer Schicker (Heidelberg) Bound-free pair production Juni 19, 2015 1 / 8

SLIDE 2

Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest

Secondary ion beams by electromagnetic interactions Bound-free pair production Double bound-free pair production A trigger on electromagnetic processes The bound-free pair constrained photon-photon luminosity Physics interest

Rainer Schicker (Heidelberg) Bound-free pair production Juni 19, 2015 2 / 8

SLIDE 3

Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest

Secondary Pb-beams at hadron colliders

magn. rigidity:

Bρ = Z

A p q

sec. Pb-beams:

Z A = 82 208

Pb80+

208

Pb81+

208

Pb82+

207

Pb82+

206

✲

cold section: dipoles John Jowett, Workshop on photon-induced collisions at the LHC, CERN, june 2-4, 2014 Active collimators - detectors ? active collimators:

◮ at LHC: not possible

(no space)

◮ at FCC: up for discussion Rainer Schicker (Heidelberg) Bound-free pair production Juni 19, 2015 3 / 8

SLIDE 4

Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest

Single and multiple pair production

single pair production: free e+e− bound-free e+e−

σBorn(e+e−,PbPb,LHC) ∼ 200 kb σBFPP(PbPb,LHC) ∼ 270 b per beam

double bound-free pair production

σ2xBFPP(PbPb,LHC) > 6 mb (priv. comm. V.Serbo)

Rainer Schicker (Heidelberg) Bound-free pair production Juni 19, 2015 4 / 8

SLIDE 5

Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest

Multiple pair production

production of bound-free pair with a free pair

Rainer Schicker (Heidelberg) Bound-free pair production Juni 19, 2015 5 / 8

SLIDE 6

Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest

Trigger on electromagnetic processes

✄ ✂

..✄

✄ ✄ ✗

trigger Pb81+

☛ ✡ ✟ ✠

..

❈ ❈ ❈ ❈ ❈ ❖

central barrel

✄ ✂

..✄

✄ ✄ ✗

trigger Pb81+

☛ ✡ ✟ ✠

..

❈ ❈ ❈ ❈ ❈ ❖

central barrel Forward trigger on Pb81+ with measurement in central barrel free e+e−, µ+µ−, τ +τ − - pairs π+π− and K+K− - pairs γγ → X →Bound-free pair constrained photon-photon luminosity

Rainer Schicker (Heidelberg) Bound-free pair production Juni 19, 2015 6 / 8

SLIDE 7

Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest

Bound-free pair constrained photon-photon luminosity

Free muon pair production

d2L(st) dω1dω2 = dσAA→AAµµ dω1dω2σγγ→µµ = dn(ω1) dω1 dn(ω2) dω2 = 4Z 4α2 π2ω1ω2 log γ Rω1 log γ Rω2

Free muon pair plus bound-free pair production

d2Lbfree dω1dω2 = dPµµ(b) dω1dω2σγγ→µµ Pee(b, Z1, Z2)d2b= Z4α2 π4ω1ω2 F(b)Pee(b, Z1, Z2)d2b

with F(b) = ∞

R d2b1d2b2 b2

1b2 1

δ(b1 − b2 − b) ≈ 4π

b2 log b 2R

integration over b: main contribution from 2R < b < 1/me, where Pee(b, Z1, Z2) ∼ A = 1.65 · 10−3 (Art. et al)∗

d2Lbfree dω1dω2 = A 4Z4α2 π2ω1ω2

1 2Rme

2 ,

d2Lbfree dω1dω2 ∼ O(10−3) d2Lst dω1dω2 (Art. et al)∗: A.N. Artemyev, V.G. Serbo, A. Surzhykov, European Physical Journal C74 (2014), 2829. Rainer Schicker (Heidelberg) Bound-free pair production Juni 19, 2015 7 / 8

SLIDE 8

Secondary beams Bound-free pair prod. Double bound-free pair prod. A trigger Constrained luminosity Physics interest

Physics topics in tagging bound-free secondary beam

cross section bound-free pair production

◮ unitarity, Coulomb corrections ?

cross section double bound-free pair production

◮ σ(Pb81+Pb81+) = 2 x σ(Pb82+Pb80+) ? ◮ unitarity, Coulomb corrections ?

Multiple lepton pair production Pion/Kaon pair photoproduction γγ → low mass resonances Total γγ-hadronic cross section beyond resonance region γγ → γγ: light-by-light scattering by lepton loops, quark loops or monopole loop.

Rainer Schicker (Heidelberg) Bound-free pair production Juni 19, 2015 8 / 8