440 likes | 565 Views
Electron and Neutrino Interactions on Nucleons and Nuclei in the Next Decade. A New International Effort led by Rochester Bridging Nuclear and High Energy Physics Programs Bridging the fields of Electron and Neutrino Interactions
E N D
Electron and Neutrino Interactions on Nucleons and Nuclei in the Next Decade A New International Effort led by Rochester • Bridging Nuclear and High Energy Physics Programs • Bridging the fields of Electron and Neutrino Interactions • Bridging QCD and Electroweak Interactions (e.g. Neutrino Oscillations) • Investigating Form Factors, Quark-Hadron Duality in Nucleons and Nuclei with electrons and neutrinos • Bridging Physics between Jlab, Fermilab and JHF-(JPARC) Principal Investigators from Rochester • S. Manly -electron scatteringJlab Hall B CLAS data- Final statesin quasielastic, resonance and DIS in nuclei - New Program • A. Bodek, (C. Keppel) - electron scatteringJlab Hall Cexperiments (structure functions, form factors, resonances in nuclei, sum rules) - E94-110+ E02-109, E02-103, P03-110 - New Program • K. McFarland, (C. Keppel, J. Mofin) - Neutrino scattering cross sections FNAL-MINERvA - Near Detector - New Program • K. McFarland - Neutrino Oscillations (JHF-SuperK, FNAL-off axis) - New Neutrino Oscillations Program -both near and far detectors Steve Manly and Arie Bodek, Univ. of Rochester
US National Academy of Science National Research Council Report 2002 In the first decade of the 21st Century, new discoveries are expected in the fast growing “areas on the boundaries between the established disciplines” Examples that come to mind are: Nuclear and Particle Physics Physics/Astrophysics Astronomy Physics and Biology-Genetics-Medical Physics Physics and Computer Science Computer Science and Biology-Genetics And others… Steve Manly and Arie Bodek, Univ. of Rochester
Within the discipline of Physics, we can make new Discoveries by drawing the expertise of physicists Across the various disciplines of Nuclear Physics, Particle Physics, Astrophysics In 2001 The Annual NuInt conferences were started and focused on A two overlying unifying goals “Neutrino Oscillations” “QCD and Nuclear Structure” Drawing on contributions from Nuclear, Particle, and Astrophysics and To study Neutrino Oscillations Requires Understanding of non-perturbative QCD Steve Manly and Arie Bodek, Univ. of Rochester
Connection to Physics at Jlab - Electrons as Probes of Hadron/Nuclear Structure QCD. Connection to Astrophysics -Solar and Atmospheric Neutrinos Also : Is CP Violation (CPV) in the Lepton sector which can lead to Leptogenesis a possible origin of Matter-Antimatter Asymmetry in the Universe ? Steve Manly and Arie Bodek, Univ. of Rochester
SuperK Water Cerenkov Detector Atmospheric neutrinos - up down asymmetry - Discovery of muon neutrino --> t neutrino oscillations. DM2 (2->3) with large mixing Maximal mixing, and evidence of muon neutrinos oscillating To t neutrinos DM2 (2->3) Steve Manly and Arie Bodek, Univ. of Rochester
"Indications of Neutrino Oscillation in a 250 km Long-baseline Experiment” The K2K collaboration, M.H. Ahn et al, hep-ex/0212007, Phys. Rev. Lett. 90 (2003) 041801. Expected (dashed black line =44 events, observed 29 events). Both normalization and shape indicate oscillations. Precise cross section and flux in the 0.3 to 5 GeV region needed. K2K, First Accelerator Based neutrino oscillations experiment. Dip at the number of expected quasielastic events at 0.7 GeV. - low statistics Comparison of rate of muon neutrino events to prediction versus energy gives a measurement of DM2 (2->3) Steve Manly and Arie Bodek, Univ. of Rochester
Very low DM2 (1->2) With large mixing. Steve Manly and Arie Bodek, Univ. of Rochester
Steve Manly and Arie Bodek, Univ. of Rochester GOOD NEW FOR FUTURE CPV large mixing (1->2)
Next generation Neutrino experiments aim at measuring the 3x3 mixing matrix and masses. This is done by looking for transformation of muon neutrinos to electron neutrinos at the 1-3 GeV region. Expect a rate of about 3%. Present limit is about 10% at SuperK 3-generation fit not as good as CHOOZ Limit Steve Manly and Arie Bodek, Univ. of Rochester
Plan for next 10 year program at JHF and Fermilab Requires good knowledge of cross sections FNAL Off axis JHF to SK Steve Manly and Arie Bodek, Univ. of Rochester
Good News: Solar mixing is LARGE - GOOD FOR CPV Challenge:We Also NEED PRECISION NEUTRINO and composition of final states -------- 1 Pion production/ resonances ---- Quasielastic W=Mp ------total including DIS W>2GeV /En 1 En(GeV) 0.1 10 Bubble Chamber language. - Exclusive final states Resonance language. - Excitation Form Factors of Resonances and decays Deep Inelastic Scattering -PDFs and fragmentation to excl. final states NEED to Understand Hadron/Nuclear Physics both at Low and High Energies Steve Manly and Arie Bodek, Univ. of Rochester
e-P scattering A. Bodek PhD thesis 1972 [ PRD 20, 1471(1979) ] Proton Data Electron Energy = 4.5, 6.5 GeV Data ‘The electron scattering data in the Resonance Region is the “Frank Hertz Experiment” of the Proton. The Deep Inelastic Region is the “Rutherford Experiment” of the proton’ SAID V. Weisskopf * (former faculty member at Rochester and at MIT when he showed these data at an MIT Colloquium in 1971 (* died April 2002 at age 93) MIT SLAC DATA 1972 e.g. E0 = 4.5 and 6.5 GeV What do TheFrank Hertz” and“Rutherford Experiment” of the proton’ have in common? A: Quarks! And QCD Steve Manly and Arie Bodek, Univ. of Rochester
(e/ m /n-N cross sections at low energy X = 1 (quasi)elastic F2 quasi integral=0.43 Very large e-p • Neutrino interactions -- Quasi-Elastic / Elastic (W=Mp) nm + n --> m- + p (x =1, W=Mp) Described by form factors (And also need to account for Fermi Motion/binding effects in nucleus) e.g. Bodek and Ritchie (Phys. Rev. D23, 1070 (1981) Resonance (low Q2, W< 2) nm + p --> m- + p + np Poorly measured , Adding DIS and resonances together without double counting is tricky. 1st resonance and others modeled by Rein and Seghal. Ann Phys 133, 79, (1981) Deep Inelastic • nm + p --> m- + X (high Q2, W> 2) • well measured by high energy experiments and well described by quark-parton model (pQCD with NLO PDFs), but doesn’t work well at low Q2 region. 1st resonance GRV94 LO (e.g. SLAC data at Q2=0.22) Issues at few GeV : Resonance production and low Q2 DIS contribution meet. The challenge is to describe ALL THREE processes at ALL neutrino (and electron) energies
What do we want to know about low energy electron/ nm reactions and why Intellectual Reasons: Understand how QCD works in both neutrino and electron scattering at low energies -different spectator quark effects. (There are fascinating issues ) How is fragmentation into final state hadrons affected by nuclear effects in electron versus neutrino reactions. Of interest to : Nuclear Physics/Medium Energy, QCD/ Jlab communities IF YOU ARE INTERESTED in QCD Practical Reasons: Determining the neutrino sector mass and mixing matrix precisely requires knowledge of both Neutral Current (NC) and Charged Current(CC) differential Cross Sections and Final States These are needed for the NUCLEAR TARGET from which the Neutrino Detector is constructed (e.g Water, Carbon, Iron)-of interest to Particle Physics/ HEP/ FNAL /KEK/ Neutrino communities IF YOU ARE INTERESTED IN NEUTRINO MASS and MIXING. Astrophysics community interested in both
At Rochester we have a long tradition of collaboration • BetweenNuclear Physics and Particle Physics, and expertise in both electron scattering and neutrino physics. • PHOBOS at RHIC(Manly)- Currently Funded by DOE Nuclear Physics Division (Manly’s PhD Thesis was in neutrino physics).---> Evolving towards Jlab Hall B and Hall C expts. • SLAC Experiments E139, E140, E140x - EMC Effect, precision nucleon and nuclear structure functions: Bodek (co-spokesperson) Funded by DOE Nuclear Physics Division in 1980’s-1990s (initially started as collaboration between A. Bodek and Tom Cormier). Provided the upgrades needed for the NPAS program at SLAC. Provided world’s standard data sets for F2, R, and EMC effects on nucleons and nuclei ----> Now evolving towards Jlab Hall C experiments. • CCFR/NuTeV Neutrino Program (Bodek, McFarland)-funded by DOE High Energy Physics from 1977-now --> Evolving towards Neutrino Program at Fermilab (MINERvA and JHF). • Phenomenological description of low energy electron and neutrino scattering (Bodek- in collaboration HEP experimenters and theorists, and nuclear community e.g. J. Arrington) More Jlab data needed
Proposed Rochester Program Jlab Hall Cexperiments (structure functions, form factors, resonances in nuclei, sum rules) - join 3 Jlab approved experiments on H and D , and propose a 4th on nuclear targets used in neutrino experiments (C, Fe, etc). E94-110 H2 Resonances F2 ,R- Completed -Join this experiment to participate in data analysis E02-109 D2 Resonance F2, R- Approved to run in 2004. - Join this experiment to take D2 resonance data. -- Proposed to PAC24 to run P03-110 at same time as E02-109. P03-110 - Resonance F2, R for Nuclear Targets used in Neutrino Experiments. - Leading this experiment (got favorable response from PAC24 - deferred with regret and will considered again in PAC25 to run at same time as D2 experiment E02-109) E02-103 H2, D2 High Q2 resonance data (and EMC effect in He3, He4) - approved by PAC24 to run in 2004 (J. Arrington). - Join this experiment to get H2 and D2 high Q2 data. Also include in overall analysis data from F2, R in nuclei at the DIS region from SLAC E140, E140x- high Q2 (Bodek), and Jlab 99-118 - DIS low Q2 (A. Brull, Keppel)
Importance of Hadronic Final States in Electron And Neutrino Scattering Hall B Program Steve Manly and Arie Bodek, Univ. of Rochester
JHF region 0.7 GeV FNAL region 3 GeV Steve Manly and Arie Bodek, Univ. of Rochester JHF region 0.7 GeV
FNAL region 3 GeV JHF region 0.7 GeV Steve Manly and Arie Bodek, Univ. of Rochester
Start with: Quasielastic: C.H. Llewellyn Smith (SLAC).Phys.Rept.3:261,1972 Updated recently By Bodek, Budd and Arrington 2003 Axial Vector Vector form factors From electron scattering Via CVC Vector Neutrino experiments use Dipole form factors with Gen=0 -Because this is what was put in the LS paper (not exactly correct) Steve Manly and Arie Bodek, Univ. of Rochester Axial form factor from Neutrino experiments
Budd, Bodek, Arrington BBA-2003 Form Factor Fits to SLAC/JLAB data. Vector Nucleon form factors display deviations from dipole. Controversy on Gep high Q2 What does axial form factor Fa do between 1 and 3 GeV2 ???? Steve Manly and Arie Bodek, Univ. of Rochester
K2K Near detector data on Water was Fit with wrong Vector Form factors. New BBA2003 form factors and updated M_A have a significant effect on Neutrino oscillations Results. Steve Manly and Arie Bodek, Univ. of Rochester
Updating Neutrino Axial Form Factors:--> Use new BBA-2003 Precise Vector Form Factors as input to neutrino data. With BBA-2003 Form Factors, Axial Vector M_A=1.00. However, no information on Axial form factor for Q2>1 GeV2. Future: Very High Statistics neutrino data will be available on Carbon. Need precise vector form factors, as modified in Carbon (including effect of experimental cuts) Can measure F_A(Q2)/ GM_V(Q2) at High Q2 - By combining Jlab and MINERvA data Quasielastic Old Bubble Chamber Data on D2. (Steve Manly was A member of this collaboration (as a PhD Thesis student) Steve Manly and Arie Bodek, Univ. of Rochester
Measure F_A(Q2)/GM_V(Q2) by comparing neutrino And electron e-e’-p data on Carbon with 1 Million events Steve Manly and Arie Bodek, Univ. of Rochester
One Example: Precise measurement of Axial Form factor of the Nucleon can only be done using a combined analysis (with the same cuts) of a sample of e-e’-p data from electron scattering at Jlab (on Carbon) with the Corresponding n - m’- p data from neutrino scattering On Carbon and using same cuts (on final state proton etc). (measure F_A at high Q2 for first time). Since future high statistics neutrino data will only be done with nuclear targets (e.g. scintillator), Nuclear Effects can both be studied, as well as cancelled by performing a combined analysis of these two data sets. Goal of our program in Hall B: Produce well understood DSTs of e-e’ X on Carbon that can be used in a combined analysis with neutrino data. Start with quasielastic, and continue on to resonances, and DIS. In the process, also do physics such as nuclear transparency, modification of resonance and DIS final states in nuclei, etc. Steve Manly and Arie Bodek, Univ. of Rochester
Duality, QCD Sum Rules, and Current Algebra Sum Rules. Local duality and Global duality appears to work for Q2 > 1.5 GeV2 in electron scattering: This is basically a consequence of the fact that if target mass effects are included, higher twists are small and QCD sum rules are approximately true for Q2 > 1.5 GeV2 . (e.g. momentum sum rule - quarks carry about 1/2 of the proton momentum) F2eP, F2eN are related to PDFs weighted by quark charges). At high Q2, duality also seems to work for nuclear corrections. All of these break down at low Q2. A complete model which works at all energies must relate electrons to neutrino structure functions and form factors within a theoretical framework. For DIS it is parton distributions, for quasielastic it is form factors (I=1/2) and for resonances it is excitation form factors for a combination of I=1/2 and I=2/3 states. Needs to work at ALL Q2 (Also, need to add the axial vector form factors, which cannot be determined from electron scattering) What happens at low Q2 ? Steve Manly and Arie Bodek, Univ. of Rochester
Adler Sum rule EXACT all the way down to Q2=0 includes W2 quasi-elastic S. Adler, Phys. Rev. 143, 1144 (1966) Exact Sum rules from Current Algebra. Sum Rule for W2DIS LIMIT is just Uv-Dv =1 b- = W2 (Anti-neutrino -Proton) b+ = W2 (Neutrino-Proton)q0=n Axial W2 = non zero at Q2=0 Axial W2 =1 at high Q2, Inelastic Elastic gA=(-1.267)2 Q2=0 Elastic gA = 0 high Q2 Adler is a number sum rule at high Q2 DIS LIMIT is just Uv-Dv. Elastic Vector =1 Q2=0 Elastic Vector = 0 high Q2 =1 is F2-= F2 (Anti-neutrino -Proton) = n W2 F2+= F2 (Neutrino-Proton) = n W2 we use: d q0) = d (n n )d Vector Part of W2, 0 at Q2=0, 1 at high Q2-Inelastic [see Bodek and Yang hep-ex/0203009] and references therein at fixed q2= Q2 Steve Manly and Arie Bodek, Univ. of Rochester + Similar sum rules for W1, W3, and strangeness changing structure functions
Outline of a Program in Investigating Nucleon and Nuclear Structure at all Q2 - Starting with PR 03-110 - Focusing on Resonance Region in Hall C in this talk and backup slides) • Update Resonance Vector Form Factors and Rvector of the large number of resonances in the Nucleon, e.g. within Rein-Seghal-Feynman Quark Oscillator model (and other resonance models) by fitting all NEW- F2 and R Electron Resonance data E94-110 (H, F2 and R) (just taken in 2003) (+ previous SLAC + photoproduction+ and other data) aim at adding E02-109 (D, F2 and R), E02-103 (H and D F2 at high Q2) and PR03-110 (nuclear targets in summer 04)nuclear targets at the same time as E0109 (D)] • Improve on Inelastic Continuum modeling of Vector F2 and R (e.g. using a formalism like Bodek/Yang) using Jlab, SLAC, H and D data, photoproduction and HERA data - and Add neutrino data from CHORUS on Pb. (for DIS Axial scattering) • Within these models, convert EM Vector Form Factor to Weak Vector Form Factors - use the Various isospin rules I=1/2 and I=3/2 of elastic, resonance and inelastic Form Factors fits to H and D data E94-110, E02-109 • Investigate if the Model predictions for Vector Scattering in neutrino reactions satisfy QCD sum rules and duality at high Q2 and Adler Vector Rum rules at ALL Q2. • Investigate if the Models predictions for Axial scattering in neutrino reactions satisfy QCD sum rules and duality at high Q2 and Adler Axial Rum rules at ALL Q2. Steve Manly and Arie Bodek, Univ. of Rochester
Apply nuclear corrections for DIS and resonance region to predict Neutrino and Antineutrino data on nuclei from PR 03-110 - Requires 5 days of running - Also use E99-118 and SLAC E140 and other for DIS A dependence. Compare predictions to existing low statistics neutrino data and to new precise neutrino data to become available in a couple of years (MINERvA, and JHF- Japan) - Do predictions from models (which satisfy all sum rules and duality) also model the neutrino and antineutrino data well? In parallel - Final states in nuclear targets to be investigated in a collaboration with Hall B experiments in electron experiments and in newneutrino experiments. Things can be learned from electron scattering Things that are learned in neutrino scattering • Nucleon +Resonance Vector Form Factors, Vector Continuum F2 at all Q2, Rvectror=sL/sT in great details. • Nuclear effects on various targets in res, and quasielastic region as a function of Q2 • Hadronic Final Stares in electron scattering • Check on Current Algebra sum rules and understanding duality - • Axial vector contribution to F2 at low Q2 • Different nuclear effects in neutrino scatt. • Account for Raxial different from Rvector • Hadronic final states in neutrino scattering Collaborative approach between High Energy and Nuclear Physics community High x and low Q2 PDFs for e/neutrino, Resonance form factors, nuclear corrections 1.Electron scattering exp.starting with JLAB P03-110 - with investigation of final states 2.New Near Detector neutrino exp. at Fermilab-NUMI/JHF - -->Years of data e.g. MINERvA + JHF Steve Manly and Arie Bodek, Univ. of Rochester
We will be submitting a proposal to DOE Nuclear Physics Division to fund a Rochester group at Jlab (building on the Rochester SLAC E140 nuclear physics group group and the Rochester PHOBOS nuclear physics group). • Rochester will be a Liaison between Electron Scattering and Neutrino Scattering communities, and lead several effort • A combined analysis of electron and neutrino data (in collaboration with other high energy and nuclear experimentalists and theorists). • A program of measurement and analysis of cross sections, form factors and structure functions on nuclear targets in Hall C. Hall C experimenters are enthusiastic about this collaboration - Bodek is leading this effort by joining E02- • A program of measurement and analysis of hadronic final states in Hall B - CLAS collaboration is enthusiastic about this participation - Here the CLAS collaboration (and not the PAC) approves the program. Professor Manly will be leading this effort. Participants • A. Bodek , S. Manly , K. McFarland - Experimental faculty • Also (D. Koltun, L. Orr, S. Rajeev - Collaborating theory faculty) • 2 students, J. Chovjka, G.B. Yu- Experimental PhD students) - to be stationed at Jlab • 2 postdocs to be stationed at Jlab (1 for Hall C and one for Hall B) Steve Manly and Arie Bodek, Univ. of Rochester
Some relevant results from previous DOE-Nuclear Funded Program at Rochester (SLAC E139, E140, E140x) Steve Manly and Arie Bodek, Univ. of Rochester
Correct for Nuclear Effects measured in e/m expt. In DIS and resonance regionFe/D data Red Jlab Resonance Green DIS Data E87, E139, E140 TM DIS Region Comparison of Fe/D F2 data In resonance region (JLAB) Versus DIS SLAC data In TM (C. Keppel 2002). These results are from Rochester Results of SLAC E87, E139, E140 Steve Manly and Arie Bodek, Univ. of Rochester MUST USE TM
Initial quark mass m I and final mass,mF=m *bound in a proton of massM -- Summary: INCLUDE quark initial Pt) Get x scaling (not x=Q2/2Mn )for a general parton Model q=q3,q0 xIs the correct variable which is Invariant in any frame : q3 and P in opposite directions. x PF= PF0,PF3,mF=m* PF= PI0,PI3,mI P= P0 + P3,M Special cases: (1) Bjorken x, xBJ=Q2/2Mn , x, -> x For m F2 =m I 2=0 and Highn2, (2) Numeratorm F2 : Slow Rescalingxas in charm production (3) Denominator: Target mass term x =Nachtman Variable x =Light Cone Variable x =Georgi Politzer Target Mass var. (all the same x ) Please derive this on the plane Most General Case: (Derivation in Appendix) ‘w= [Q’2 +B] / [ M (1+(1+Q2/2) ) 1/2+A] (with A=0, B=0)<<<<<<<< where2Q’2 =[Q2+ m F2 -m I 2] + { (Q2+m F2 -m I 2 ) 2 + 4Q2 (m I 2+P2t) }1/2 Bodek-Yang 2002-2003: Add B and Ato account for effects of additional m2 from NLO and NNLO (up to infinite order) QCD effects.
Bodek/Yang Modified GRV98 PDFs To DIS Data Fit to electron And muon Scattering DIS data. Predict reson. Photo and Neutrino data 2 = 1268 / 1200 DOF Dashed=GRV98LO QCD F2 =F2QCD (x,Q2) Solid=modified GRV98LO QCD F2 = K(Q2) * F2QCD(x w, Q2) Steve Manly and Arie Bodek, Univ. of Rochester
How well does it work? Predict Resonance, Neutrino And photoproduction data Steve Manly and Arie Bodek, Univ. of Rochester