Mass hierarchy and CP violation with upgraded NOνA and T2K in light of large θ 13

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1 Mass hierarchy and CP violation with upgraded NOνA and T2K in light of large θ 13 Suprabh Prakash Department of Physics Indian Institute of Technology Bombay Mumbai, India September 26, 212 Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

2 This talk is based on the following works: SP, S. K. Raut, S. U. Sankar, Getting the best out of T2K and NOνA, Phys. Rev. D 86, 3312 (212) arxiv: S. K. Agarwalla, SP, S. K. Raut, S. U. Sankar, Potential of optimized NOνA for large θ 13 and combined performance with a LArTPC and T2K, arxiv: Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

3 Outline Introduction Recent reactor neutrino results The superbeam experiments: P µe channel Hierarchy-δ CP degeneracy Reoptimized NOνA, for large θ 13 and NOνA upgrades Mass hierarchy sensitivity Leptonic CP violation sensitivity Results and Summary Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

4 The physics of neutrino oscillations Neutrinos are massive and they mix As they travel, they can oscillate from one flavor to another The physics of flavor oscillations can solely be explained by quantum mechanics Quant. Mech. description Neutrino oscillations are sensitive to 6 parameters: 3 mixing angles: θ 12, θ 13 and θ 23 A leptonic CP violating phase: δ CP 2 mass squared differences between the 3 mass eigenvalues: 21 = m 2 2 m2 1 and 31 = m 2 3 m2 1 Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

5 Present status of neutrino oscillations Best fit points, 1σ & 3σ ranges for various neutrino parameters (after Neutrino 212): [Gonzalez-Garcia,Maltoni,Salvado,Schwetz, arxiv:hep-ph/ v2] Global sin 2 2θ 13 best-fit:.89 Best final precision on sin 2 2θ 13 : Daya Bay: 5% Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

6 The unknowns in neutrino oscillations physics Mass hierarchy We do not know whether the hierarchy is Normal: m 1 < m 2 m 3 or Inverted: m 3 m 1 < m 2? Leptonic CP violation Whether CP is violated in the leptonic sector? i.e. is P(α β) P(ᾱ β)? Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

7 Recent θ 13 measurements by reactor neutrino experiments Updated results from Reactor Neutrino Experiments (reported at Neutrino 212): Daya Bay: sin 2 2θ 13 =.89 ±.11(stat) ±.5(syst), 7.7σ for non-zero θ 13 RENO: sin 2 2θ 13 =.113 ±.13(stat) ±.19(syst), 4.9σ for non-zero θ 13 Double CHOOZ: sin 2 2θ 13 =.19 ±.3(stat) ±.25(syst), 3.1σ for non-zero θ 13 Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

8 Implications of a large θ 13 Nature has been very friendly to us with θ 13 Present and future generation Superbeam experiments have a very good scope of performing well With present generation superbeam experiments, one can get significant hints about both hierarchy and δ CP And, if we are lucky with δ CP also, the present generation superbeam experiments will be able to establish hierarchy as well However, establishing CP violation and measuring the phase δ CP might not be possible even with such a large θ 13 Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

9 The superbeam experiments An intense beam of neutrinos directed towards a detector Most experiments plan to run in both ν as well as ν mode The beams primarily consists of the µ-type ν/ ν; contaminations are also present which lead to backgrounds The beam is directed towards a detector which in general is located far-off and the beam travels entirely through the earth which leads to matter effects The distance that the beam travels i.e. the baseline, is important The beam profile i.e. the E ν at which the flux peaks, is also important Finally, in the detector, one looks for electron appearance i.e. ν µ which have oscillated to ν e Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

10 The P µe oscillation channel ν µ ν e oscillation probability, expanded perturbatively in α = 21 / 31 : P µe = sin 2 2θ 13 sin 2 θ 23 sin 2 ˆ (1 Â) (1 Â) 2 where ˆ = 31 L/4E +α cos θ 13 sin 2θ 12 sin 2θ 13 sin 2θ 23 cos( ˆ sin ˆ Â sin + δ CP ) ˆ (1 Â) Â 1 Â +α 2 sin 2 2θ 12 cos 2 θ 13 cos 2 sin 2 ˆ Â θ 23 Â 2 Â = A/ 31 Wolfenstein matter term: A(eV 2 ) = ρ(gm/cc)e(gev). Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

11 Dependence of P µe on the baseline P µe (as a band in δ CP ) vs. Energy Left panel: L=295 km & Right panel: L=81 km Probability(neutrinos) NH IH δ CP = +9 o δ CP = -9 o sin 2 2θ 13 = km Probability(neutrinos) NH IH δ CP = +9 o δ CP = -9 o sin 2 2θ 13 =.1 81 km Go Back E(GeV) E(GeV) The value of P µe scales with L The position of 1st Oscillation maxima also scales with L Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

12 Various LBL superbeam experiments Present generation LBL superbeam experiments MINOS: 735 km T2K: 295 km NOνA: 81 km Next generation LBL superbeam experiments CERN-Frejus: 13 km T2HK: 295 km CERN-Canfranc: 63 km CERN-Gran Sasso: 73 km CERN-Homestake: 13 km CERN-Pyhasalmi: 23 km Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

13 The P µe oscillation channel: degeneracies The P µe channel Has sensitivity to all the neutrino parameters Pros: This feature, in principle, makes measurement of all neutrino parameters possible using superbeam Cons: This very feature handicaps it of various degeneracies A measurement of P µe will have Intrinsic or (δ CP, θ 13 )-degeneracy Hierarchy or sign( 31 )-degeneracy Octant or θ 23 -degeneracy This leads to an eight-fold degeneracy in determination of θ 13 and δ CP. [Barger et. al., hep-ph/112119] Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

14 The P µe oscillation channel: degeneracies But, the reactor neutrino experiments are independent of these degeneracies as they are independent of δ CP and matter-effects (hence hierarchy) and therefore, they have provided a very clean measurement of θ 13. In this work, we have assumed a precise information of θ 13. Hence the degeneracies relevant for us are: hierarchy-δ CP degeneracy Octant or θ 23 -degeneracy We further assume the maximal value of sin 2 2θ 23 = 1 and, for the moment, ignore the octant degeneracies. So, the degeneracy relevant for this work is hierarchy-δ CP degeneracy Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

15 Hierarchy-δ CP degeneracy P µe (as a band in δ CP ) vs. Energy Left panel: Neutrinos & Right panel: Anti-neutrinos Probability(neutrinos) NH IH δ CP = +9 o δ CP = -9 o sin 2 2θ 13 =.1 81 km Probability(anti-neutrinos) NH IH δ CP = +9 o δ CP = -9 o sin 2 2θ 13 =.1 81 km E(GeV) E(GeV) Lower half plane ( 18 δ CP ): favourable plane for NH Upper half plane ( δ CP 18 ): favourable plane for IH Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

16 Resolving the hierarchy-δ CP degeneracy The hierarchy-δ CP degeneracy can be resolved in following ways: 1 Including atmospheric data 2 The Magic baseline proposal [Barger et. al., hep-ph/112119; Huber and Winter, hep-ph/31257] 3 By combining data from more that one channels like: ν e ν µ or ν e ν τ [Donini et. al., hep-ph/2634] 4 The Bimagic baseline proposal 5 By combining data from more than one LBL superbeam experiments [Barger et. al., hep-ph/112119] Option 1 is a free source, but for a good hierarchy sensitivity, huge statistics are required. While options 2 and 3 are futuristic and challenging to implement, options 4 and 5 are more feasible Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

17 The Bimagic baseline P µe (as a band in δ CP ) vs. Energy for 254 km Left panel: Neutrinos & Right panel: Anti-neutrinos Probability(neutrinos) NH IH δ CP = +9 o δ CP = -9 o sin 2 2θ 13 = km Probability(anti-neutrinos) NH IH δ CP = +9 o δ CP = -9 o sin 2 2θ 13 = km E(GeV) E(GeV) Clean separation between NH and IH around 1st Osc. maxima One of the hierarchy loses its δ CP dependence around 3 GeV and the other is amplified Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

18 The Bimagic baseline References for 254 km: [Raut et. al. arxiv: , Phys.Lett.B696: ,211] [Dighe et. al. arxiv:19.193, Phys.Rev.Lett.15:26182,21] [Joglekar et. al. arxiv: , Mod.Phys.Lett.A26: ,211] CERN-Pyhasalmi (L=23 km), one strong contender for the LBL superbeam experiment in Europe, is very close to the bimagic baseline Very good sensitivity to mass hierarchy even with very moderate exposures [Dusini et. al. arxiv:129.51] Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

19 NOνA and T2K Characteristic NOνA T2K Baseline 81 km 295 km Location Fermilab-Ash River J-PARC-Kamioka Beam NuMI beam.8 off - axis JHF beam 2.5 off - axis Beam power.7 MW.75 MW Beam peaks at 2 GeV.6 GeV P µe 1st Osc. Maximum 1.5 GeV.55 GeV Detector TASD, 14 kton Water Čerenkov, 22.5 kton Runtime 3 in ν+3 in ν 5 in ν Simulation Details Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

20 Hierarchy sensitivity of NOνA NOνA with various design statistics Left panel: NH is true & Right panel: IH is true True:NH / Test:IH, 9% C.L True:IH / Test:NH, 9% C.L NOνA 1.5*NOνA 3*NOνA 12 6 δ CP (true) δ CP (true) NOνA 1.5*NOνA 3*NOνA sin 2 2θ 13 (true) sin 2 2θ 13 (true) For the bestfit, 9% C.L. hint for the whole of favourable half plane Almost no sensitivity in the unfavourable half plane, even with larger statistics Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

21 Hierarchy sensitivity of NOνA + T2K NOνA + T2K with nominal design statistics Left panel: NH is true & Right panel: IH is true True:NH / Test:IH, 9% C.L True:IH / Test:NH, 9% C.L NOνA+T2K δ CP (true) δ CP (true) NOνA+T2K sin 2 2θ 13 (true) sin 2 2θ 13 (true) Adding the T2K data helps in the unfavourable half plane; but insufficient for the bestfit No difference in the favourable half plane Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

22 Resolving hierarchy-δ CP degeneracy using two different LBL experiments Event sample observed in the detector has to be analyzed assuming a true mass hierarchy. If the assumption is right, we get a right estimate of δ CP ( χ 2 min occuring at right δ CP). If the assumption is wrong, we get a wrong estimate of δ CP ( χ 2 min occuring at wrong δ CP). measurement has degenerate solutions: (hier right, δ CP right ) and (hier wrong, δ CP wrong ) For a given experiment, (sin δ CP right sin δ CP wrong ) A E L for that experiment [O. Mena and S. Parke, arxiv:hep-ph/487] E81 km peak flux 3 E295 km peak flux (sin δ right wrong CP sin δ CP NOνA ) 3 (sin δ CP right wrong sin δ CP T2K ) δ wrong CP predicted by two LBL experiments with different matter effects are different (also evident from the P µe vs. E plots ) Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

23 Resolving hierarchy-δ CP degeneracy using two different LBL experiments [ χ 2 min ] NOνA at (hier right, δ right CP ) and (hier wrong wrong, δ CP NOνA ) [ χ 2 min ] T2K at (hier right, δ right CP ) and (hier wrong wrong, δ CP T2K ) [ χ 2 ] NOνA not minimal at (hier wrong wrong, δ CP T2K ) [ χ 2 ] T2K not minimal at (hier wrong wrong, δ CP NOνA ) [ χ 2 min ] NOνA+T2K not at (hier wrong wrong, δ CP NOνA ) or (hierwrong wrong, δ CP = wrong solutions excluded T2K ) Caveat: In order to have reasonable excluding sensitivity, χ 2 min value at (hier wrong, δ wrong CP ) should be much larger than χ 2 min value at (hierright, δ right CP ). Therefore, the experiments must have enough statistics. Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

24 How does combining data from two LBL help? χ 2 vs. δ CP (test) plots for NOνA Left panel: favourable half plane & Right panel: unfavourable half plane *NOνA True sin 2 2θ 13 :.1 True δ CP = -18 o True δ CP = -135 o True δ CP = -9 o True δ CP = -45 o *NOνA True sin 2 2θ 13 :.1 True δ CP = True δ CP = 45 o True δ CP = 9 o True δ CP = 135 o χ True:NH / Test:IH χ True:NH / Test:IH δ CP (test) χ 2 min always occurs around 9 χ 2 min δ CP (test) large for fav. half plane, very small for unfav. half plane Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

25 How does combining data from two LBL help? χ 2 vs. δ CP (test) plots for T2K Left panel: favourable half plane & Right panel: unfavourable half plane χ *T2K True sin 2 2θ 13 :.1 True δ CP = -18 o True δ CP = -135 o True δ CP = -9 o True δ CP = -45 o True:NH / Test:IH χ *T2K True sin 2 2θ 13 :.1 True δ CP = True δ CP = 45 o True δ CP = 9 o True δ CP = 135 o True:NH / Test:IH δ CP (test) δ CP (test) Right panel: large χ 2 where χ 2 min of NOνA was almost Right panel: χ 2 min occurs at test δ CP different from that of NOνA Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

26 How does combining data from two LBL help? χ 2 vs. δ CP (test) plots for 1.5*NOνA +2*T2K Left panel: 1.5*NOνA only & Right panel: 1.5*NOνA +2*T2K True (sin 2 2θ 13, δ CP ) = (.1, 9 o ) χ 2 = 2.71, 9% C.L. True:NH / Test:NH True:NH / Test:IH True (sin 2 2θ 13, δ CP ) = (.1, 9 o ) χ 2 = 2.71, 9% C.L. True:NH / Test:NH True:NH / Test:IH *NOνA *NOνA+2*T2K χ 2 2 χ δ CP (test) δ CP (test) Left panel: A large range of wrong δ CP compatible with wrong hierarchy Right panel: Adding T2K data almost eliminates this wrong δ CP range Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

27 How does combining data from two LBL help? χ 2 vs. δ CP (test) plots for 1.5*NOνA +2*T2K Left panel: 1.5*NOνA only & Right panel: 1.5*NOνA +2*T2K True (sin 2 2θ 13, δ CP ) = (.1, -9 o ) χ 2 = 2.71, 9% C.L. True:IH / Test:NH True:IH / Test:IH True (sin 2 2θ 13, δ CP ) = (.1, -9 o ) χ 2 = 2.71, 9% C.L. True:IH / Test:NH True:IH / Test:IH *NOνA *NOνA+2*T2K χ 2 2 χ δ CP (test) δ CP (test) Left panel: A large range of wrong δ CP compatible with wrong hierarchy Right panel: Adding T2K data almost eliminates this wrong δ CP range Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

28 Reoptimization and upgrades in NOνA, post-large θ 13 We study the physics reach of the reoptimized NOνA (in conjunction with T2K) to determine the mass hierarchy and CP violation There is considerable enthusiasm in the NOνA and LBNE collaborations for an additional small liquid argon detector at the Ash River site We consider the possiblility of such a module Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

29 Reoptimized NOνA Previous optimization: done under the assumption sin 2 2θ 13 = with objective to have least background New optimization: for moderately large θ 13 with relaxed cuts for event selection criteria which allow more signal and background [talk by R. Patterson in NuFACT 12] The main differences between the old criteria and new criteria are: The signal efficiencies for new NOνA are higher than that of old one by roughly a factor of 2 for neutrino events The background acceptance has also increased The NC spectrum shift to the measured energies is implemented through migration matrices. [LBNE Collaboration, T. Akiri et al. arxiv: ] We have taken care of the neutrino contamination in the anti-neutrino beam Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

30 Liquid Argon TPC A 1 kt liquid argon time projection chamber (LArTPC) constructed close to NOνA A signal efficiency of 8% for e ± compared to 45% for TASD [LBNE Collaboration, T. Akiri et al. arxiv: ] The energy resolution and background rejection for the LArTPC and TASD are comparable Such a detector will come on line much later than NOνA In considering NOνA + LArTPC, we assume equal 6 years ν and ν runs for NOνA and equal 3 years ν and ν runs for LArTPC Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

31 Mass hierarchy sensitivity with upgraded NOνA and T2K Hierarchy discovery for various set-ups Left panel: TASD vs. LArTPC for NH true & Right panel: Combined set-up for NH true Mass Hierarchy Discovery, NH true NOvA (3+3) 5 kt LAr (3+3) 1 kt LAr (3+3) 14 kt LAr (3+3) 3 25 Mass Hierarchy Discovery, NH true NOvA (3+3) + T2K (5+) NOvA (6+6) + T2K (5) + 5 kt LAr (3+3) NOvA (6+6) + T2K (5) + 1 kt LAr (3+3) 1 2 χ % C.L. 9% C.L δcp (true) δcp (true) Left panel: LArTPC of mass 1 kt can be as effective as 14 kton TASD Right panel: With the addition of a 1 kt LArTPC, close to 95% C.L. hierarchy discrimination becomes possible for all the values of δ CP χ % C.L. 9% C.L Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

32 Mass hierarchy sensitivity with upgraded NOνA and T2K Hierarchy discovery for various set-ups Left panel: TASD vs. LArTPC for IH true & Right panel: Combined set-up for IH true Mass Hierarchy Discovery, IH true 3 25 Mass Hierarchy Discovery, IH true 1 2 χ % C.L. 9% C.L χ 2 15 δ CP (true) δcp (true) Left panel: LArTPC of mass 1 kt can be as effective as 14 kton TASD Right panel: With the addition of a 1 kt LArTPC, close to 95% C.L. hierarchy discrimination becomes possible for all the values of δ CP % C.L. 9% C.L Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

33 Sensitivity of upgraded NOνA and T2K for CP violation Leptonic CP violation discovery for various set-ups Left panel: TASD vs. LArTPC for NH true & Right panel: Combined set-up for NH true CP Violation Discovery, NH true NOvA (3+3) 5 kt LAr (3+3) 1 kt LAr (3+3) 14 kt LAr (3+3) 95% C.L CP Violation Discovery, NH true NOvA (3+3) + T2K (5+) NOvA (6+6) + T2K (5+) + 5 kt LAr (3+3) NOvA (6+6) + T2K (5+) + 1 kt LAr (3+3) χ 2 3 9% C.L. χ % C.L. 9% C.L δcp (true) δ CP (true) Left panel: LArTPC of mass 1 kt can be as effective as 14 kton TASD Right panel: Addition of a 1 kt LArTPC significantly improves range of true δ CP for which CP conservation can be ruled out at 95% C.L. Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

34 Sensitivity of upgraded NOνA and T2K for CP violation Leptonic CP violation discovery for various set-ups Left panel: TASD vs. LArTPC for IH true & Right panel: Combined set-up for IH true 6 CP Violation Discovery, IH true 16 CP Violation Discovery, IH true χ % C.L. 9% C.L χ % C.L. 9% C.L δ CP (true) δcp (true) Left panel: LArTPC of mass 1 kt can be as effective as 14 kton TASD Right panel: Addition of a 1 kt LArTPC significantly improves range of true δ CP for which CP conservation can be ruled out at 95% C.L. Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

35 Can hier-δ CP degeneracy be resolved by first measuring δ CP? Can a short LBL experiment such as T2K(295 km) or CERN-Frejus(13 km) measure the δ CP phase independent of hierarchy with electron appearance channel? A short baseline has small matter effects and therefore is relatively free of hierarchy-δ CP degeneracy. Therefore, it is expected that it can provide a clean δ CP measurement. But it cannot!! Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

36 Can hier-δ CP degeneracy be resolved by first measuring δ CP? Allowed δ CP plots for T2K[3+3] Left panel: Hierarchy known & Right panel: Hierarchy not known 18 True:NH/Test:NH, 9% C.L. 18 True:NH/Test:IH, 9% C.L δ CP (test) δ CP (test) δ CP (true) δ CP (true) Left panel: allowed range of test δ CP is around true δ CP Right panel: large region of the wrong half-plane also Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

37 Can hier-δ CP degeneracy be resolved by first measuring δ CP? Allowed δ CP plots for CERN-Frejus(13 km) Left panel: Hierarchy known & Right panel: Hierarchy not known 18 True:NH/Test:NH, 9% C.L. 18 True:NH/Test:IH, 9% C.L δ CP (test) δ CP (test) δ CP (true) δ CP (true) Left panel: allowed range of test δ CP is around true δ CP Right panel: large region of the wrong half-plane also Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

38 δ CP phase measurement with upgraded NOνA and T2K δ CP phase measurement Left panel: NOνA +T2K & Right panel: NOνA +T2K+LArTPC 18 True:NH/Test:NH 9% C.L. 18 True:NH/Test:NH 9% C.L δ CP (test) δ CP (test) δ CP (true) δ CP (true) A precise δ CP phase measurement will require a future facility Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

39 Summary A 1 kt LArTPC is found to be equivalent to new NOνA in its ability to exclude the wrong hierarchy and CP violation discovery For increased exposure for NOνA, the combination of data from NOνA, LArTPC and T2K (nominal) can determine hierarchy at almost 2σ level for all the values of δ CP NOνA by itself can discover CP violation only for a small fraction of the favourable half-plane, and only at 9% C.L. Addition of data from T2K causes a remarkable increase in the range of δ CP for which CP violation can be established With the combination of additional data from the LArTPC detector with boosted NOνA and nominal T2K, CP violation can be discovered at 95% confidence level for around 6% of the entire δ CP range Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

40 Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

41 n flavor eigenstates ν α ; connected to n mass eigenstates ν i through unitary PMNS mixing matrix U. ν α = U αi ν i i ν e ν µ ν τ U = = U ν 1 ν 2 ν 3 U e1 U e2 U e3 U µ1 U µ2 U µ3 U τ1 U τ2 U τ3 U = U 23 (θ 23 ) U 13 (θ 13, δ) U 12 (θ 12 ) U Maj Schroedinger s Eq. in matter : i d dt ν α = H flav matt ν α P (α β) = δ αβ 4R j>i U αi U βiu αj Uβj jil sin2 4E + 2I j>i U αi U βiu αj Uβj jil sin 2E ji = m 2 j m 2 i Go Back Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

42 Go Back Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

43 Go Back Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

44 Go Back Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39

45 Go Back Suprabh Prakash (IITB) INFN, Padova visit - Sep / 39