the jefferson laboratory and the italian collaboration physics (excerpt)

IFAE 2012 / Ferrara E. Cisbani / Experimental Physics at JLab 1

27 Settembre 2013XCIX Congresso SIF 2013 – Trieste

G.M. Urciuoli, M. Battaglieri

L’esperimento JLAB12 The Jefferson Laboratory and the Italian collaboration Physics (excerpt)

• Nucleon Structure (Form Factor and Quark Distribution)• Parity Violation Experiments• Hypernuclei• Nuclear Structure

Technological Developments• HD Polarized Target• Photon Tagger• RICH/Clas12• GEM/SiD Trackers

2

Thomas Jefferson National Laboratory

• Newport News / Virginia / USA (3 ore da Washington DC)

• DOE funding + Local Universities and Organizations

• Director: H. E. Montgomery (ex-associate director for research al Fermilab)

• 2000 International Users• Fundamental Research by electron

accelerator on 3+1 experimental Halls• Applied research by FEL and other facilities• Web site: www.jlab.org

more than

3

CEBAF accelerator

A B C

Lina

c

Linac

Arc

Arc

Injector

• Linear Recirculating e- Accelerator with

superconductive cavities• Polarized beam

• High current (200 mA)• Max. energy 6 GeV

• 100% duty factor• Beam released

simultaneously on three experimental Halls: A, B

and C

4

Hall A Hall B/CLAS Hall CTwo High Momentum

Resolution + one large angular acceptance spectrometers

Dedicated neutron and gamma detectors

Large acceptanceHigh multiplicity

reconstructionSix coils Toroidal

field

Two asymmetric spectrometers

High momentum range and high resolution

Dedicated detectors

High beam currents (>100 mA), lumi 1037

cm-2 s-1

Tagged real photons beam

High beam currents (>100 mA), lumi 1037

cm-2 s-1

3He T/L Polarized target, high flexibility unpol. from H to Pb

NH3/ND3 Polarized long. target

NH3/ND3 Polarized long. target, high flexibility unpol. from H to Pb

Large and flexible installations

4p coverage Moderately large and flexible installations

Current Experimental Halls

5

CEBAF after 2013

CHL-2

Upgrade magnets and power supplies

add Hall D (and beam line)6 GeV CEBAF (< 2013)

Max Current: 200 mAMax Energy: 0.8 - 5.7 GeVLong. Polarization: 75-85%

12 GeV CEBAF

(>2013)Max Current: 90 mAMax Energy Hall A,B,C: 10.9 GeVMax Energy Hall D: 12 GeVLong. Polarization: 75-85%

$ 310M

6

Hall A Hall B/CLAS12 Hall C Hall D/GLUEX+ 1 large angular and

momentum, high lumi spectrometer with hadron ID

+ Solid detector+ Möller detectorNew beam line

New ~2p toroid detector with extended hadron ID

+ “super high” momentum spectrometer

+ dedicated equipment

Excellent hermetic coverage,

Solenoid fieldHigh multiplicity

reconstruction

+ lumi 1038 cm-2 s-1 + forward tagger for quasi-real photons

108 linearly polarized <12 GeV

real photons/s

+ targets with large thickness

+ long/trans polarized H/D target

hallaweb.jlab.org www.jlab.org/Hall-B www.jlab.org/Hall-Cwww.jlab.org/Hall-D

www.gluex.org

Experimental Halls after 2014

7

JLab physics• Origin of quark and gluon confinement (B & D)– Gluonic excitations - existence and properties of exotic mesons (and baryons)– Heavy baryon and meson spectroscopy

• Structure of the Hadrons (A,B and C)– Parton Distributions Functions (and Fragmentation Functions)– New view of nucleon structure via the Generalized Parton Distributions (GPDs)

accessed in Exclusive Reactions– Form Factors - improve knowledge of charge and current in the nucleons;

constraints on the GPDs– Quark propagation and hadron formation

• Dynamics of the nucleons in the nuclei (A, B and C)– The Quark Structure of Nuclei (resolving the EMC effect)– The Short-Range Behavior of the N-N Interaction and its QCD Basis– Cold nuclear matter

• Electroweak Interaction (A and C)– High Precision Tests of the Standard Model at low energies via Parity-Violating

Electron Scattering Experiments– Measure nuclear properties by weak interaction

8

Sezioni INFN partecipanti (BA, CA, CT, GE, FE, ISS, LNF, PD, RM, RM2, TO):Ricercatori + Tecnologi: ~ 60 (41.2 FTE)

Intensa attività sperimentale al JLab/6 GeV (prevalentemente in sala A e B) Forte coinvolgimento negli sviluppi legati al raddoppio di energia del fascio e aggiornamento degli apparati nelle sale sperimentali

Esperimento INFN formalmente attivo

dal 2009 per 7 anni, nasce dalla

sinergia delle ex sigle AIACE + LEDA

per sfruttare al meglio le opportunità

sperimentali offerte

dall’aggiornamento a 12 GeV

TMD’s latest results at JLab

9

First ‘direct’ measurement on neutron

n - Collins small, largely compatible to 0; Sivers negative (?) for p+, zero for p-

Collins Moment = h1 Collins FF Clean probe of relativistic effects

Sivers Asymmetry = f1T TMD Unpol. FF

Link to quark Orbital Angular Momentum

Experimental limits:Modest statistics, integrated on the relevant kinematical variables (x,z,pT),no access to large x, valence region, no clean interpretation of the data.

Adapted from A. Puckett, JLab 2011

D

F TMDs @ JLab 12 GeV

E12-09-018: p/kE12-10-006: p

3He

Hall A SBS/SOLID

HALL CHMS+SHMS

E12-09-017: p/kC12-11-102 p0

Hall BCLAS12

C12-11-111: p/k

H2, D2NH3HDH2, NH3, D2,

ND3

E12-06-112: pE12-09-008: k

E12-07-107: pE12-09-009: k

A Multi-Hall TMDs program - Large variety of targets- Different species of detected hadrons

-High luminosity experiments- Extended phase space

Adapted from P. Rossi, JLab 2012

10

E12-11-107: p

C12-11-108: p

11

Proton Form Factors

2tan

2)( e

p

ebeam

l

t

Mp

Ep

MEE

PP

GG mm

Polarization transfer from the incident electron to the scattered proton

22MpEp GG

dd

Rosenbluth Separation: assume single photon approximation

Prior to JLab, expectations were that Gep/GMp was fairly constant with Q2

New focus on nucleon structure and description of elastis scattering (two photon exchange); possible role of quark OAM

e + p → e’ + p’

e→ + p → e’ + p →’

At JLab, new class of experiments show GE/GMp decreasing linearly with Q2

Extended measurements of p/n form factors at high Q2

Test different models (including different contributions from the quark OAM)

Investigate the transition region (perturbative / non perturbative)

Constraint the H and E GPDs

Electromagnetic Nucleon Form Factors @12GeVE-12-07-109: Polarization transfer E-12-09-016: Double polarization

E-12-09-019: Cross section ratio

12

0Z

e e

+

2

Esperimenti di Violazione della Parità• Misura accurata della asimmetria nei processi elastici (e DIS) di elettroni

polarizzati longitudinalmente su nucleone/nucleo non polarizzato

• Accesso alle costanti di accoppiamento deboli elettroni-quark (u/d) delle correnti neutre, ovvero alla corrente debole del protone, ovvero all’angolo di mixing debole

• Pone limiti su esistenza di nuova fisica (PVDIS, QWeak, Möller) • Ha permesso la misura del contributo dei quark s ai fattori di forma del

nucleone (HAPPEX, G0)• Permette la misura di importanti grandezze nucleari soppressi nei

processi elettromagnetici PREX

13

A neutron skin established at ~93 % CL

Neutron Skin = RN - RP = 0.33 + 0.16 - 0.18 fm

Neutron Radius = RN = 5.78 + 0.15 - 0.17 fm

Pins down the symmetry energy (1 parameter)

14

First direct measurement of the neutron skin

PREX-II Approved by PAC (Aug 2011)

Lead (208Pb) Radius Experiment: PREXE = 850 MeV, =6° electrons on lead

15

Future equipment for PaVi experiments at Jlab/Hall A

SOLID (PV e- - q scattering + SIDIS) - PV e-quark - High precision TMD Parity Violation Physics to test the SM at low energy: require high luminosity and

precise control of the systematics

16

Publ

ished

Study Λ-N Interaction potential

Hypernuclei at JLab

Experimental requirements:- Excellent Energy Resolution- Detection at very forward angles (6°→septum magnets)

- Excellent PId for kaon selection →RICH- High luminosity

Reactions Investigated: 9Be→9LiΛ (3 spin doublets, information on Δ)

12C→12BΛ (evidence of excited core states → sN contribution)

16O→16NΛ (unmatched peak may indicate large sΛ term)

H →Λ,Σ0 (elementary process)

Experiment E94-107Hypernuclear spectroscopy9Be (e,e’k+) 9

ΛLi reaction

Thanks to energy resolution improvements a clear three peak structure appears in the excitation energy spectrum. RM1, ISS

Analisi dell’esperimento sulla produzione di ipernuclei a Jlab completamente in mano alla collaborazione italiana:- M. Iodice, F. Cusanno et al., Phys. Rev. Lett. 99, 052501 (2007) (ipernucleo 12

ΛB) - F. Cusanno, G.M. Urciuoli et al., Phys Rev. Lett. 103 202501 (2009) (ipernucleo 16

ΛN) - G.M. Urciuoli, F. Cusanno, S. Marrone et al. Sottomesso a PHYS REV C

Experiment E06-007208Pb(e,e’p)207Tl and 209Bi(e,e’p)207Pb cross sections at true

quasielastic kinematics (xB=1, q=1 GeV/c, ω=0.433 GeV/c ) and at both sides of q Never been done before for A>16 nucleus

RM1, ISS

★ Determine the spectroscopic factors dependence with Q2

★ Long range correlations: not needed!★ Relativistic effect in nuclei: needed!

Search for dark force: HPS in Hall-B

18

19

- - - - - - - - - - - - 1 week 1.1 GeV

- - - - - - - - - - - - 1 week 2.2 GeV

3 months 2.2 GeV

3 months 6.6 GeV

Bump hunting

Bump hunting+ vertexing

Phase 1expected 2014/15

Phase 22015 or later

HPS Projected results

JLab1212 GeV era / Equipment

• HD Target,

• Forward Tagger,

• RICH,

• High Lumi Tracker

HD-ice: polarized frozen spin HD targetPolarized target of high dilution factor, made of solid Deuterium-Hydride:Longitudinal and Transverse Polarizations: up to 75% H and 40% DRelaxation time: > 1 year Polarization procedure » 3 monthsData taking: » monthsWide acceptance

Target cell

Comparison of signal over background ratio:HD versus conventional polarized target

INFN contribution:• Dilution Refrigerator• Contribution to the construction of the new In-

Beam Dilution Refrigerator Cryostat• Raman analysis of ortho-hydrogen and para-

deuterium contents in HD gas• Magnetic Vari-Temp Cryostat for HD

condensation and NMR polarization measurements

Target Transfer

In-beam cryostat

Run with polarized deuterons from HD-ice & circularly polarized photons started on Dec. 2011: D polarization 27%

Run with polarized deuterons from HD-ice & linearly polarized photons started on April 2012: D polarization 30%

Test of HD-ice & electron beam performed in February: on-going analysis

21

The Forward Tagger for CLAS12

22

New system to detect electrons at small angle and perform quasi-real photo-production experiments

Calorimeterelectron energy/momentumPhoton energy (ν=E-E')Polarization ε-1 ≈1 + ν2/2EE’PbWO4 crystals with APD/SiPM readout

Scintillation Hodoscopeveto for photonsScintillator tiles with WLS readout,…

Trackerelectron anglesPolarization scattering planeMicroMegas detectors

Moller Shield

CalorimeterTracker

Scintillation Hodoscope

HTCC Moller cup

GEMC implementation

e-*

CLAS12

p

e-

ForwardTagger

Adapted from M. Battaglieri, Genova 2012 22

AerogelElliptical mirrors

Photo-detectors

+ Planarmirrors

Proximity Focusing RICH + MirrorsRICH Conceptual Design

Goal: reduce the photon detection area of MA-PMTs H8500 to ~ 1m2/sector

Elliptical and planar mirrors to focus the Cherenkov light of particles emitted at angles > 12°

10 H8500

8 R8900

- Test with hadron beam at CERN with a prelininary RICH prototype (summer 2011)

number of Np.e obtained for direct ring in consistent with simulations- Test with electron beam at LNF (july 2012)- test of full prototype with p/K beam at CERN (august 2012) 23

UvaJLabINFNRutgers U.College WMU. of GlasgowNorfolk State U.Carnegie Mellon U.U. of New Hampshire

SBS Spectrometer in Hall A

SiD

High luminosity ~1039/s/cm2 Moderate acceptanceForward angles Reconfigurable detectors

24

40x150 cm2 GEM Tracker70 mm spatial resolution

High photons up to 250 MHz/cm2 and electrons 160 kHz/cm2 background

Spare

RICH detector for CLAS12DC R3R2R1

EC

Torus

TOF

PCAL

HTCC

Solenoid

LTCC

INSTITUTIONS

ARGONNE NL

INFNBari, Ferrara, Genova, Frascati, Roma/ISSGLASGOW U.JLABU. CONNUTFSM (Chile)

GeV/c

1 2 3 4 5 6 7 8 9 10

p/K

p/p

K/p

TOFHTCC

LTCC

TOF

TOF

LTCCHTCC

full pion / kaon / proton separation in 2–8 GeV/c range

p/K separation of 4-5 @ 8 GeV/c for a rejection factor ~1000

x RICH

Aerogel mandatory to separate hadrons in the 2-8 GeV/c momentum range collection of visible Cherenkov light use of MA-PMTs

Option under investigation:proximity focusing RICH + mirrors (innovative geometry)

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CLAS12 PID

RICH

GeV/c 1 2 3 4 5 6 7 8 9 10

p/K

p/p

K/pe/p

HTCC

TOF

TOF

TOF

HTCC

HTCC

HTCCEC/PCAL

LTCC

RICHRICH

LTCCRICHLTCCLTCCRICHLTCCRICH

4-5 p/K separation @ 8 GeV/c

Aerogel mandatory to separate hadrons in the 2-8 GeV/c momentum range collection of visible Cherenkov light use of PMTs

Challenging project, crucial to minimize Detector area

Option under investigation: proximity focusing RICH + mirrors

IFA

E 20

12 /

Ferr

ara

E. C

isba

ni /

Expe

rimen

tal P

hysi

cs a

t JLa

b27Adapted from P. Rossi, JLab 2012

New RICH geometry

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Aerogel

Flat Mirror + Aerogel Active Photon Detector

Adapted from L. Pappalardo Roma 2011

RICH preliminary prototype

10 H8500

8 R8900

Aerogel

MA-PMTs

Electronics

Maroc2 front end electronics developed for nuclear medicine• preamplifier, adjustable from 1/8 to 4• ADC, about 80fC per channel

Hit distributions

Ebeam

(GeV)Aerogel <d>

(cm)<R(p)>

cmt (cm) n

10 1 1.05 35.1 11.210 2 1.05 34.6 11.110 3 1.05 34.1 10.910 3 1.03 48.8 12.04 1 1.03 49.8 12.2

N.B. 1 and 2 cm means 2 or 3 blocks of 1 cm

1cm 2cm 3cm

aerogel n=1.03

aerogel n=1.05

integrated distributions of hits above

threshold3cm

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Meson Spectroscopy in CLAS12The study of the light-quark meson spectrum and the search for exotic quark-gluon configurations is crucial to reach a deep understanding of QCD:• identify relevant degrees of freedom• understand the role of gluons and the origin of

confinementPhoto-production is the ideal tool:• linearly polarized photon beam (NEW!)• large acceptance detector (CLAS12)

Forward TaggerE’ 0.5-4.5 GeVn 7-10.5 GeVq 2.5-4.55 degQ2 0.007 – 0.3 GeV2

W 3.6-4.5 GeVPhoton Flux 5 x 107 /s @ Le=1035

Quasi-real photoproduction with CLAS12(Low Q2 electron scattering)

e-γ*

CLAS12

p

e-

ForwardTagger

Tracker Electron angle

Hodoscope Photon veto

Calorimeter Electron Momentum/EnergyAdapted from R. De Vita, Roma/2011

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Choice of the technology

System RequirementsTracking Technology

Drift MPGD Silicon

High Background Rate (up to):(low energy and e) 1 MHz/cm2

NO MHz/mm2 MHz/mm2

High Resolution (down to):70 mm

Achievable 50 mm 30 mm

Large Area:from 40×150 to 80×300 cm2

YES Doable Very Expensive

… and modular: reuse in different geometrical configurations Flexibility in readout geometry

and lower spark rate

GEM mMs

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GEM working principle

Ionization

Multiplication

Readout

Multiplication

Multiplication

Readout independent from ionization and multiplication stages

Recent technology: F. Sauli, Nucl. Instrum. Methods A386(1997)531

GEM foil: 50 mm Kapton + few mm copper on both sides with 70 mm holes, 140 mm pitch

Strong electrostatic field in the GEM holes

SBS Tracker GEM Chambers configuration

Modules are composed to form larger chambers with different sizes

Electronics along the borders and behind the frame (at 90°) – cyan and blue in drawing

Carbon fiber support frame around the chamber (cyan in drawing); dedicated to each chamber configuration

Front TrackerGeometry

x6

Back Trackers Geometry

X(4+4)

GEp(5) SBS

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MonteCarlo + Digitazation + Tracking

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High + e background hits~ MHz/cm2

(Signal is red)

Bogdan Wojtsekhowski + Ole Hansen+ Vahe Mamyan et al.

6 GEM chambers with x/y readoutUse multisamples (signal shape)

for background filtering

Assembling the first 40x50 cm2 module

Stretching

Gluing the nextframe with spacers

Foil Tension: T = 2 kg/cmSpacer Sector: S = 170 cm2Expected maximum pressure on foil P 10 N/m2

Maximum foil deformation:u 0.0074 * P * S / T = 6.4 mm

Use stretching and spacersto keep foil flat

Stretcher design from LNF / Bencivenni et al.

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Beam test @ DESY / Full Module Size 40x50 cm2

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Electronics Readout (GEM and SiD)

GEM FEC MPD DAQ

2D R

eado

ut

75 mm

49.5

mm

8 mm

Up to 10mtwisted,shielded

copper cable(HDMI)

Passive backplane(optional)

Main features:• Use analog readout APV25 chips (analog and time information)• 2 “active” components: Front-End card and VME64x custom module • Copper cables between front-end and VME• Optional backplane (user designed) acting as signal bus, electrical

shielding, GND distributor and mechanical support

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+ Small Silicon Detector

Track

Angular Range

Chamber doubletDipole

SD(x/y)

21 Set 2009 / CSN III JLab12 - E. Cisbani 39

5mm

5mm

10mm

10mm

8.5mm8.5mm6.5mm

A

A

B

B

C

C

D

D103500

Disegno custom per JLAB12da un wafer di 6” (152mm)

40

30 cm

23 cm

41

fori di fissaggio

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Fan Out PCB

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Equipment / Physics Matrix @ 12 GeV

EquipmentPhysics

HDTarget RICH Forward

TaggerGEM

TrackerSi

Detector

TMDs, nucleon

spin structure

X X X X

Meson Study X

Form Factors X X

Parity Violating Electron

ScatteringX

Intensa attività di sviluppo tecnologico per un esteso programma di fisica

43

The “ultimate” description of the nucleon

3D view of the nucleon

Transverse Momentum Dependent (TMD) parton distribution and fragmentation functions • Describe correlations between the transverse

momentum of quarks/gluons and spin• 3D picture of nucleon in momentum space

Generalized Parton Distribution functions (GPD) • Describe correlations between the transverse

coordinates of quarks and spin• 3D picture of nucleon in mixed momentum and

transverse spaceN

ucle

on

Quark

Information on: nucleon spin origin, quark orbital angular momentum,relativistic effects in QCD, quark/gluon Q2 evolution,

QCD gauge invariances ...

44Adapted from P. Rossi, JLab 2012

Some TMDs projections

SOLID: e3He →e’p+/-X

E12-11-007

E12-09-009

CLAS12: e p →e’K+/-X longitudinally polarized target

6 GeV data

SBS: e3He →e’K+/- X(transverse target)

E12-09-018 45Adapted from P. Rossi. JLab 2012

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Different (e,e’h) experimental configurationsExperiments Luminosity

(s·cm2)-1

Tracking Area(cm2)

ResolutionAngular(mrad)

Vertex(mm)

Momentum(%)

GMn - GEn up to 7·1037 40x150 and 50x200

< 1 <2 0.5%

GEp(5) up to 8·1038

40x120, 50x200 and

80x300

<0.7~1.5

~ 1 0.5%

SIDIS up to 2·1037 40x120,40x150 and

50x200

~ 0.5 ~1 <1%

Maximum reusability: same trackers in different setups

Most demanding

HighRates

LargeArea

Down to ~ 70 mmspatial resolution

47

Confinement Mechanism

(hadronization and spectroscopy)

Hadronization of quarks

48

H. Matevosyan et al., Phys. Rev. D85 (2012) 014021

Transverse momentum distributions in hadronization may be flavor dependent

Employ nuclei as analyzers of hadronization processes, to probe:- The hadronization formation length

(0-10 fm)

- The time scale on which a qq pair becomes dressed with its own gluonic field

Study the SIDIS reaction on nuclei;

observables:

- The hadronic multiplicity ratio

- The transverse momentum broadening

Adapted from P. Rossi, JLab 2012 E12-06-117

How hadrons form inscattering processes ?

Beyond the quark model: hybrids and exotics

mesons

Quarks are confined inside colorless hadronsthey combine to 'neutralize' color force

baryons

Other quark-gluon configuration can give colorless objects

QCD does not prohibit such states but not yet unambiguously observed

qq

q qq

molecules glueball mesons hybrid mesonspentaquarks

qqq

q

q

q

q q

qqq

Adapted from M. Battaglieri, Genova 2012 49

Hybrid mesons and glueballs mass range

1.4 – 3.0 GeV

Lattice-QCD predictions for the lowest exotics states:

0+- 1.9 GeV1-+ 1.6 GeV

This mass range is accessible in photoproduction experiments with a beam energy in the range 5 GeV < E <12 GeVPerfectly matched to JLab12 energy!

QCD Lattice calculations

Exotics

ρ

Standard mesons

J.Dudek et al Phys.Rev.D82 (2010) 034508

Adapted from M. Battaglieri, Genova 2012 50

Unambiguous experimental signature for the presence of gluonic degrees of freedom in the spectrum of mesonic states

S=S1+S2 J= L+S P = (-1) L+1 C= (-1) L+S

Combine excited glue quantum number with those of the quarks

Normal meson:flux tube in ground statem=0CP=(-1) S+1

Hybrid meson:flux tube in excited statem=1CP=(-1) S

Flux tube JPC 1-+ , 1+-

Search for mesons with 'exotic' quantum numbers(not compatible with quark-model)

Not-allowed: JPC = 0-- , 0+- , 1-+ , 2+- ...

Meson spectroscopy with photons at JLab

Adapted from M. Battaglieri, Genova 2012 51

Hall-D - GlueX Detector Hall-B - CLAS12 Detector

Meson spectroscopy with photons at JLab-12 GeV

• Good resolution• Good pID• Reasonable hermeticity• Un-uniform acceptance

• Good hermeticity• Uniform acceptance• Limited resolution• Limited pID

Forward Tagger

• Determination of JPC of meson states requires PWA• Decay and production of exclusive reactions• Good acceptance, energy resolution, particle identification

52Adapted from M. Battaglieri, Genova 2012