Physics of n-a. Ulrich Mosel

Transcription

1 Physics of -A Ulrich Mosel

2 A Wake-up Call

3 Essetial Refereces: GiBUU 1. Buss et al, Phys. Rept. 512 (2012) 1 cotais both the theory ad the practical implemetatio of trasport theory 2. Gallmeister et al., Phys.Rev. C94 (2016), cotais the latest chages i GiBUU Mosel, A. Rev. Nucl. Part. Sci. 66 (2016) 171 short review, cotais some discussio of geerators

4 A Reactio Geeral structure: approximately factorizes full evet (four-vectors of all particles i fial iitial iteractio x fial state iteractio Determies iclusive X-sectio Determies the fial state particles

5 A theory-based geerator Aim: to costruct the best possible cosistet theory framework for iclusive reactios ad full evet simulatios (NOT exclusive 1particle out or coheret). Requiremets: Relativistically correct (Skyrme-like or RMF) mometum-depedet potetials, uclear bidig, approximately correct hadlig of collisio terms Same potetials i iitial state ad fial state iteractios Fial state iteractios testable i may differet reactios, such as p+a, pi+a, A+A, e+a, gamma+a

6 GiBUU : Quatum-Kietic Theory ad Evet Geerator based o a BM solutio of Kadaoff-Baym equatios Physics cotet ad details of implemetatio i: Buss et al, Phys. Rept. 512 (2012) Mie of iformatio o theoretical treatmet of potetials, collisio terms, spectral fuctios ad cross sectios, useful for ay geerator Code from gibuu.hepforge.org, ew versio GiBUU 2016 Details i Gallmeister et al, Phys.Rev. C94 (2016) o.3,

7 Iitial iteractio: ca be ay sophisticated model à iclusive cross sectios Fial state iteractio: propagates these outgoig particles through the ucleus usig quatum-kietic trasport theory, fully relativistic à full evet, four-vectors of all particles Iitial ad fial iteractios come from the same Hamiltoia: CONSISTENCY of iclusive ad semi-iclusive X-sectios

8 The same groudstate for all processes! Differet from GENIE (NEUT), where differet processes (QE, 2p2h, ) are calculated withi differet models. Boud groudstate Differet from all geerators, also from Nieves, Martii New i GiBUU 2016: Better groud state: costat Fermi surface eforced, - 8 MeV bidig for all uclei, ot tued ew treatmet of 2p2h, cosistet with e-scatterig

9 Iclusive ad Exclusive Modellig I quatum-kietic theory the iclusive X-sectio emerges as time = 0 step for the time-developmet of the oe-body phase-space distributio of all particles ivolved:

10 Iitial State Correlatios GiBUU groud state: ucleos boud i mometum-depedet potetial, obtaied from EFT, mometum give by local Ferm gas, potetial RMF or Skyrme Eergy-distributio smooth because of x-depedet Potetial --> spectral fuctio close to realistic, but o shelleffects src Alvarez-Ruso, Hayato, Nieves True src cotributio Very small effect o Iclusive cross sectios

11 GiBUU Igrediets: 2p-2h Assume: 2p2h trasverse, structure fuctio W 1 for electros from experimetal fit of MEC cotributio by Bosted ad Mamya (arxiv: ) ad Christy (priv. comm.) to world data for 0 < W < 3.2 GeV ad 0.2 < Q 2 < 5 GeV 2 Trasverse assumptio established aroud 1990, Ericsso, Marteau

12 2p2h Q 2 -w Distributio for 2p2h From: Bosted ad Mamya, Christy W 1

13 Semi-iclusive QE Electro Scatterig a ecessary check for ay geerator developmet 0.24 GeV, 36 deg, Q 2 = 0.02 GeV GeV, 60 deg, Q 2 = 0.24 GeV 2

14 Test with Electro Data Dramatic ifluece of fsi RFG SF GiBUU Akowski, Behar, Sakuda, PR D91 (2015) 03305

15 Test with Electro Data GiBUU 2016 Akowski. Behar, Sakuta

16 Test with Electro Data GiBUU M.V. Ivaov et al, J.Phys. G43 (2016) , Scalig Agreemet with data, without explicit RPA or src!

17 Now to (Ati-) Neutrios QE, pio productio, DIS straightforward 2p2h: purely trasverse, use respose from e from: Martii et al. R st ~ W 1 from electro scatterig Same Respose i V + A as i V A ~ W 1 from Walecka 1975

18 Iclusive Lepto Kiematics Gallmeister et al. Phys.Rev. C94 (2016) o.3, p2h ~ D MiiBooNE C12 (QE + 2p2h) MicroBooNE Ar40 (fully iclusive)

19 Iclusive Lepto Kiematics Gallmeister et al. Phys.Rev. C94 (2016) o.3, NOvA C12 DUNE/LBNF Ar40

20 Compariso with T2K Data dσ/dp e (10-39 cm 2 /GeV) dσ/dcos(θ e ) (10-39 cm 2 ) total QE 2p2h DIS p e (GeV) total QE 2p2h DIS cos(θ e ) dσ/(dcosθ µ dt µ )/A (10-38 cm 2 /GeV) tot QE 2p2h DIS T µ (GeV) T µ (GeV) T2K, µ T2K, e

21 Now to Fial State Iteractios Quatum-kietic Trasport Theory (Kadaoff-Baym, 60s, Botermas-Malfliet 90s)) Basic object: ot particle (as i MC geerators), but sigle particle desity matrix: Here, for simplicity, give for o-shell particle, at time 0

22 Quatum-kietic Trasport Theory O-shell drift term Off-shell trasport term Collisio term Describes time-evolutio of F(x,p) H cotais mea-field potetials Spectral fuctio Phase space distributio KB equatios with BM offshell term

23 Iclusive ad Exclusive Modellig GiBUU takes the fial state of the first, iitial lepto-ucleus iteractios ad propagates it (i.e. all particles i it) through the uclear volume.

24 Trasparecy Trasparecy: itegral measure of i-medium iitial ad fial state effects Basic Defiitio: T = 1/A * s(a)/s(n) widely used i electro-a iteractio physics ad i i-medium physics

25 Proto Trasparecy GiBUU: full symbols Data: ope symbols JLAB, SLAC from: J. Lehr, Giesse thesis, 2003

26 w Meso Trasparecy Trasparecy T gives itegral iformatio o i-medium width G Kotulla et al, Phys.Rev.Lett. 100 (2008)

27 Hadro Trasparecy EMC: 200, 280 GeV leptos Hermes: 28 GeV Z h = E h / Distributio cotais Ifo o hadro formatio times

28 A.Airapetia et al., NPB780(2007)1 2 d 1 4 He 2 20 Ne 10 Trasparecy T 84 Kr Xe 54 For eutrios: get T distributios for T(E h ) ad T(p T2 ) Possible without recostructio

29 Proto Taggig ad Multi-Nucleos FSI cause avalache effect : oe ucleo kicks out other ucleos ad looses eergy è 2 outgoig particles ca come also from true, oe-body QE (ad DN à NN, pio absorptio)

30 Proto Taggig ad Multi-Nucleos Lalakulich et al., Phys.Rev. C86 (2012) o.1, FSI cause avalache effect : oe ucleo kicks out other ucleos ad looses eergy è 2 outgoig particles ca come also from true, oe-body QE (ad DN à NN, pio absorptio) HOWEVER: evets with oe ucleo out ca come oly from true QE

31 Proto Spectrum Trasparecies cotai itegral Ifo o imagiary parts of self-eergies Loss of flux oly, o ifo o where the flux goes. Spectra give the full story, essetial for ifluece of experimetal acceptace cuts

32 Proto Taggig ad Multi-Nucleos ear d CP = - p/2 Mosel et al, Phys.Rev.Lett. 112 (2014) far d CP = p/2 Solid: true E Dashed: recostructed E Evet rates at ear (LBNF) ad far detector (DUNE) d CP sesitivity at DUNE

33 CCQE i MiiBooNE ad NOMAD Differet Evet Selectio MiiBooNE: 1µ,0p NOMAD: 1µ,0p (1track) + 1µ,0p,1p (two-track)

34 NOMAD Evet-Rates QE ad 2p2h are very small parts of the total iteractio

35 Summary I Theory: State-of-the-art calculatios of iclusive cross sectios provide a ecessary (but ot sufficiet) check for a full descriptio of A reactios Free-Space Mote Carlo Simulatios miss the most importat aspect of uclei: potetials ad bidig! Quatum-kietic Trasport Theory is the (well established, ad i other fields of physics - widely used) method to deal with potetials ad bidig i o-equilibrium processes, allows for off-shell trasport

36 Summary II Experimet: Give data with as little geerator cotamiatio as possible. No-go is, e.g., flux cuts to mimick lepto acceptace QE-evets are experimetally idistiguishable from stuck-pio evets - > give your cross sectio for these reabsorptio evets (as MB did!). Aim for cosistecy: use the same theory to calculate both the explicit ad the reabsorbed pio evets At DUNE (ad MINERvA) DIS domiates the total evet rate. It should give iterestig ifo o W 3 i medium (EMC effect for eutrios)