Calorimeter Options for Large Acceptance PVDIS Setup

Transcription

1 Outline.Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 1 Calorimeter Options for Large Acceptance PVDIS Setup.Chudakov 1 1 Hall A, JLab Calorimeter Workshop, JLab, Oct 2008

2 Outline.Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 2 Outline 1 Motivation 2 Apparatus Requirements and options Solenoidal Large Intensity Device (SoLID) 3 Calorimeter Options

3 Outline.Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 2 Outline 1 Motivation 2 Apparatus Requirements and options Solenoidal Large Intensity Device (SoLID) 3 Calorimeter Options

4 Outline.Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 2 Outline 1 Motivation 2 Apparatus Requirements and options Solenoidal Large Intensity Device (SoLID) 3 Calorimeter Options

5 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 3 Parity Violation in lectron Scattering at Q 2 M 2 Z e e Polarized beam on Unpolarized target σ A γ + A weak 2 A γ 2 + 2A γ A weak +... γ Z f f A RL = σ R σ L σ R σ L A weak A γ G F Q 2 4πα g g = g e A GT V ± ge V GT A, depend on sin2 θ W, kinem. for f l ± g (1 4 sin 2 θ W ) < 0.05 Observable A , sensitive to: lectroweak coupling: CM tests Magnification: sin 2 θ W 0.23 δ(sin 2 θ W ) 0.02 δ(a) A Target structure unusual FF, PDF combinations

6 PV DIS Asymmetry L ehadron = G F 2 i (C 1i ja e ji V +C 2i jv e ji A ) where i are partons (quarks) C 1q = 2g e A gi V = C 1q t 3iL + 2Q ei s 2 W C 2q = 2g e V gi A = +C 2q t 3iL (1 4s 2 W ) Cahn,Gilman 1978 A Parton model: PV = G F Q 2 2 [a(x) + Y (y) b(x)] 2πα Y (y) = 1 (1 y)2 1+(1 y) 2, y = ν, x = x Bj a(x) = i f i(x)c 1i Q ei / i f i(x)q 2 ei Isoscaler target Deuterium:f (x) largely cancel q ± q ± q in proton a(x) = 3 10 (2C 1u C 1d ) (1 + R s (x)) b(x) = 3 10 (2C 2u C 2d ) (1 R a (x)) } 2s R s (x) = + large x 0 R a (x) = u + +d + u+d u + +d + A PV (x, Q 2 )/Q 2 large x A(y) b(x) = i f i(x)c 2i Q ei / i f i(x)q 2 ei f i (x) - quark distribution functions Corrections from: s-quarks, sea-quarks target mass higher twists Prescott 1979 sw 2 = 0.22 ± 0.02 using SM.Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 4

7 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 5 Measurements of the weak charges C 1q, C 2q xisting measurements: Planned measurements: PV-elastic in e p, d, Be, C at Bates, Mainz, JLab PV-DIS in e d, µ ± C at SLAC, CRN Atomic PV experiments PV-DIS in e d at Jlab 6 GeV (Hall A) x 0.3 FIG. 2: The effective couplings C1u, C1d (left), C2u and C2d (right). The future Qweak experiment (purple band), combined with the APV-Cs result (red band), will provide the most precise PV-DIS in e d at Jlab 12 GeV (Hall C) x 0.3 data and the best Standard Model test on C1u and C1d. The SAMPL result for C2u C2d at Q 2 = 0.1 (GeV/c) 2 and the projected results from the 6 GeV PVDIS experiment (05-007, Phase Remember NUTV! I+II) [13] are shown. Assuming the SM prediction of 2C1u C1d, the value of 2C2u C2d can be determined from the proposed measurement Credit to P.Reimer to (2C2u etc2d) al = (red band). p. 5

8 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 6 Program of PV DIS Study Strategy Study hadronic physics first Use the hadronic results to measure the axial couplings Required precise kinematics and broad range Two beam energies: 11, 8.8 GeV Measure A D in narrow bins of x, Q 2 with 1% precision Study the A D (Q 2 ) at 0.3 < x < 0.6 to constrain HT Search for CSV with A D (x) in 0.5 < x < 0.7 Use x > 0.4, high Q 2, Y data to measure C 2q Requires: A large acceptance and high rate magnetic spectrometer

9 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 7 DIS Parity Violation at X > 0.6 at 12 GeV, GeV <θ<35 o X Bj > 0.55 W 2 > 4 GeV 2 Q 2 > 6 GeV 2 Motivation: CSV, d/u, high twists A 10 4 Q Rate= 35.8 khz at L= 540 pb -1 s -1 4 W 2 = 4 x Bj = o W 2 = 8. x Bj = 0.75 x Bj = 0.55 Q 2 = x Bj = 35 Q 2 = o Q 2 = θ, deg

10 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 7 DIS Parity Violation at X > 0.6 at 12 GeV, GeV o W 2 = 4 W 2 = 8. 22<θ<35 o X Bj > 0.55 W 2 > 4 GeV 2 Rate= Q 2 > 6 GeV khz at L= 540 pb -1 s -1 x Bj = 0.95 x Bj = 0.75 x Bj = 0.55 Q 2 = 10. x Bj = 35 Q 2 = o Q 2 = θ, deg Motivation: CSV, d/u, high twists A 10 4 Q Kinematics and Rates 22 < θ < 35, W 2 > 4 50 µa, 40 cm LH 0.54fb 1 s 1 Rate 34kHz X > 0.55 Rate 8.7kHz X > 0.65 acceptance = 100%, eff=50% 1% stat events X > 0.55: X > 0.65: 13 days 40 days

11 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 8 Other Potential xperiments xperiments considered at 12 GeV SIDIS: transversity, etc. 2 paricles to detect γp J/Ψp photoproduction close to threshold DVCS e p e γp, e l + l p,?

12 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 9 Requirements Acceptance Working at L 0.54fb 1 s 1 > 1.5 GeV to remove low energy e, π < no line of sight, to remove γ σ / < 2% energy resolution Ω > 0.3str solid angle PID e/π 10 5 Trigger rate <20 khz/daq If it were easy - would have been done somewhere

13 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 10 Options Several options have been considered: Large solenoidal spectrometer a magnet leased from BaBar/CLO/CDF... Double-todoid spectrometer Others - much lower acceptance...

14 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 11 Solenoidal Large Intensity Detector (SoLID) Y, cm Solenoidal detector for PVDIS at high x LH target Yoke Coil Z, cm 35 o 22 o BeBar magnet Altered yoke Calorimeter >200 krad/year 50% 15 m 2 = 7 m 2 pre/shower Magnetic field 0.01 T Y, cm X,cm det 9

15 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 12 M calorimeters with optical readout Density X 0 R M λ I Refr. τ Peak Light Material g/cm 3 cm cm cm index ns λ nm yield Crystals NaI(Tl) %/ 1/4 CsI %/ 1/2 CsI(Tl) %/ 1/2 BGO %/ 1/2 PbWO /39% %/ 1/2 15/60% /01% LSO %/ 1/2 PbF Cher Cher %/ 1/2 Lead glass TF Cher Cher %/ 1/2 SF Cher Cher %/ 1/2 SF Cher Cher %/ 1/2 Sampling: lead/scintillator SPACAL %/ 1/2 Shashlik %/ 1/2 - hygroscopic Np.e. GeV rad σ

16 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 13 nergy resolution Fluctuations of the track length (M): σ c t, where t is the layer Sampling fluctuations (M): σ thickness 0.1 t in X 0 (B.Rossi), for lead absorber (t > 0.2) > 0.05 Statistics of the observed signal (M): σ > 0.01 Noise, pedestal fluctuations σ < 0.01 Calibration drifts σ 0.01 for a large detector Ideally, a large sampling calorimeter may have σ

17 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 14 SpaCal (CRN, Frascatti, Hall D) scintillating fibers / lead matrix CRN - original R&D KLO (DAFN) PMTs KLO σ/ 5.7%/ 1/2 KLO στ 50/ 1/ ps Volume: Fiber/Pb/glue 48%/42%/10% X = 1.2 cm 5 g/cm 3 Critical for this resolution: uniformity fibers collected to the Ph.Det. Ph.Det. surface: 50% PMTs only? Mag. field?

18 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 15 Shashlyk Calorimeter Pb + scintillator sandwitch WLS fibers to the Ph.Det. Ph.Det. surface 1% Pb Sc Pb Sc Pb Sc Pb Sc Pb Sc WLS fibers PMT HRA-B: PMTs σ 0.12 KOPIO: APDs σ 0.03

19 Motivation Apparatus Calorimeter Options HRA-B Calorimeter ARTICL IN PRSS ARTICL IN PRSS ARTICL IN PRSS G. Avoni et al. / Nuclear Instruments and Methods in Physics Research A 580 (2007) NIMA 580, 1209 (2007) G. Avoni et al. / Nuclear Instruments and Methods in Physics Research A 580 (2007) et al. / Nuclear Instruments and Methods in Physics Research A 580 (2007) G. Avoni Table 1 HRA-B CAL parameters Channels Cell size Absorber Radiation length ðx 0 Þ quiv. Molie re rad. Depth Volume ratio WLS Light yield (p.e./gev) PM type LD (wavelength, nm) Max. radiation dose (kgy/year) at shower-max INNRMOST/INNR MIDDL OUTR cm W Ni Fe alloy cm 1.24 cm 13 cm (23X 0 ) W:Sc ¼ 2:2 : 1 Kuraray Y R-5600/FU68 Marl (450) 50/ cm lead (Pb) cm 4.15 cm 34 cm (20X 0 ) Pb:Sc ¼ 1 : 2 BCF-91A 800 FU-84-3 L934SRCB (660) cm lead (Pb cm 4.15 cm 34 cm (2 Pb:Sc ¼ BCF-91A 1300 FU-84L934SRC 1 Fig. 2. The HRA-B electromagnetic calorimeter structure. Fig. 2. The HRA-B electromagnetic calorimeter structure. Fig. 3. INNR CAL module structure..chudakov Oct 31, 2008 Fig. 4. MIDDL CAL module structure. Calorimeter for Large Acceptance PVDIS 16

20 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 17 HRA-B Calorimeter (continue) Parameter Inner Middle Outer Channels Cell size 2.23 cm 5.59 cm cm Absorber W-Ni-Fe Pb Pb X cm cm cm Moliere 1.24 cm 4.15 cm 4.15 cm Depth in X Volume Abs/Sc 2.2:1 1:2 1:2 WLS Kuraray Y-11 BCF-91A BCF-91A p.e./gev krad/year σ σx, Y cm

21 KOPIO Calorimeter ARTICL IN PRSS G.S. Atoian et al. / Nuclear Instruments and Methods in Physics Research A 584 (2008) Photodetector APD Installation mount APD screw cap Fiber's squeeze collar 294 ARTICL IN P NIMA 584, 291 (2008) G.S. Atoian et al. / Nuclear Instruments and Methods i Monitoring fiber Rear light-tight cover Wire tensioners Rear clamp-plate of sandwich Lead/scintillator sandwich WLS fiber Lead tile "LGO" lock Scintillator tile Sandwich compression wire Front clamp-plate of sandwich Fig. tile simu mat Front light-tight cover Fig. 2. The Shashlyk modules at different stages of assembly..chudakov Fig. 1. The Shashlyk module design. Oct 31, 2008 Calorimeter for Table Large 1 Acceptance PVDIS 18

22 .Chudakov Oct 31, 2008 Calorimeter for Large Acceptance PVDIS 19 KOPIO Calorimeter (continue) Cell size 11 cm Absorber Pb mm 300 Scintillator BASF mm Hole 1.3 mm Fiber 1.0 mm Y MS Fibers/module m Fibers bunch OD 1.4 cm X 3.49 cm Moliere 5.98 cm Density 2.75 g/cm 3 Depth in X 16 Total depth 65 cm krad 100 APD API OD=16 mm Q=94% p.e./gev σ σt, ps 72 14