Arie Bodek, Univ. of Rochester1 Quasielastic Scattering at low energies at MINERvA A. Bodek, H. Budd, J. Arrington- Editors (will need the help of others soon, e.g.) Steve Manly and others

Arie Bodek, Univ. of Rochester2 Neutrino Cross Sections at Low Energy at 2 GeV, Quasielastic about 30% of events  T / E

Arie Bodek, Univ. of Rochester3  quasi-elastic neutrinos on Neutrons-( - Calculated)  quasi-elastic Antineutrinos on Protons - Calculated From H. Budd -U of Rochester (NuInt02) (with Bodek and Arrington) DATA - FLUX ERRORS ARE 10% to 20% Even with the most Up to date Form Factors The agreement With data is not spectacular Data mostly on nuclear targets are lower - Nuclear Effects are important - Need to work on nuclear corrections and chose nuclear models that describe electron quasielastic scattering - Low Q2 Next Generation Neutrino Experiments Need this to 2%

Arie Bodek, Univ. of Rochester4 Start with: Quasielastic: C.H. Llewellyn Smith (SLAC).Phys.Rept.3:261,1972 Vector form factors From electron scattering Via CVC Axial form factor from Neutrino experiments Neutrino experiments use Dipole form factors with Gen=0 -Because this is what was put in the LS paper (not exactly correct) Vector Axial Updated recently By Bodek, Budd and Arrington 2003

Arie Bodek, Univ. of Rochester5 Low-Q2 suppression or Larger M A ? T.Ishida’s From Ito NuInt02 K2K fits this With larger Ma=1.11 instead Of nominal 1.02 GeV NuInt02: Example- systematic errors that happen when one is not familiar with the latest input from electron scattering.

Arie Bodek, Univ. of Rochester6 Effect is really Low Q2 suppression from non Zero Gen Wrong Gen /Best Form Factors (Ratio) Wrong Ma=1.1 (used by K2K) Over Ma=1.02 (Ratio) If One Uses Both wrong Form Factors (used in K2K MC) ( Wrong Gen =0 +Wrong Ma=1.1) Over Best Form Factors (Ratio) --> Get right shape But wrong normalization of 10% But the true reason - as we is that the Neutrino Community was using Outdated Dipole Form Factors For E=1 GeV K2K experiment thought this was a nuclear effect on M A Can fix the Q2 dependence either way (by changing mA or using correct vector form factors). However the overall cross sections will be 10-15% too high if one chooses wrong

Arie Bodek, Univ. of Rochester7 1.05

Arie Bodek, Univ. of Rochester8 Wrong Ma=1.1 (used by K2K) Over Ma=1.02 (Ratio) gives 8% higher cross Section (1% for each 0.01 change in Ma Gen (right)/Gen=0 (wrong) gives 6% lower cross section Can fix the Q2 dependence either way (by changing mA or using correct vector form factors). However the overall cross sections will be 14% too high if one chooses wrong.

Arie Bodek, Univ. of Rochester9 CONCLUSION OF BODEK, BUDD ARRINGTON - VECTOR FORM FACTORS ARE IMPORTANT - BUT HAVE VERY GOOD DATA from JLAB- Good enough AxialVector Non zero small interference vector axial zero

Arie Bodek, Univ. of Rochester10 Fp important for Muon neutrinos only at Very Low Energy Q 2 =-q 2 UPDATE: Replace by G E V = G E P -G E N g A =-1.267,M A need to Be updated from Neutrino scatter. UPATE: Replace by G M V = G M P -G M N 1. Ma also from known pion-electroproduction. There are theory corrections here.If one believes those corrections, Ma is known also very well. 2. Ma from neutrino scattering theoretically more robust. At Q2<0.25 GeV2, there are nuclear corrections to the cross section if nuclear targets are used. However, Ma itself should not have large nuclear corrections (since Mv does not) 3. At Q2 > 1 GeV2, is the dipole form correct for Fa? (It is not for Fv).l Vector form factors From electron scattering Via CVC

Arie Bodek, Univ. of Rochester11 Neutron G M N is negativeNeutron (G M N / G M N dipole ) At low Q2 Our Ratio to Dipole similar to that nucl-ex/ G. Kubon, et al Phys.Lett. B524 (2002) Neutron (G M N / G M N dipole ) Our fit Earlier fit

Arie Bodek, Univ. of Rochester12 Neutron G E N is positive New Polarization data gives Precise non zero G E N hep-ph/ (2002) Neutron, G E N is positive - Imagine N=P+pion cloud Neutron (G E N / G E P dipole ) Krutov (G E N ) 2 show_gen_new.pict Galster fit Gen

Arie Bodek, Univ. of Rochester13 Extract Correlated Proton G M P, G E P simultaneously from e-p Cross Section Data with and without Polarization Data Proton G M P Compare Rosenbluth Cross section Form Factor Separation Versus new Hall A Polarization measurements Proton G E P /G M P Proton G M P / G M P -DIPOLE What does Ga do between 1 and 3 GeV2?

Arie Bodek, Univ. of Rochester14 Examples of Current Low Energy Neutrino Data: Quasi-elastic cross section - Flux errors are about 10% to 20% now  tot /E Next generation experiments need these cross sections to 1% to get precise neutrino mixing angles

Arie Bodek, Univ. of Rochester15 Effect of G M N + (G M P,G E P using POLARIZATION data AND non zero G E N Krutov) - Versus Dipole Form -> Discrepancy between G E P Cross Section and Polarization Data Not significant for Neutrino Cross Sections - since dominated by Q2<1 G M P,G E P extracted With e-p Cross Section data only G M P,G E P extracted with both e-p Cross section and Polarization data ratio_JhaKJhaJ_D0DD.pict ratio_JKJJ_D0DD.pict using cross section data AND G E N Krutov Using Polarization Transfer data AND G E N Krutov +n->p+  - +p->n+  + +n->p+  - +p->n+  + Note - from Arrington If difference is two photonExchange effects, then Gep at Low Q2 changes by 3% - to be studied

Arie Bodek, Univ. of Rochester16 Reanalysis of Experiment 1

Arie Bodek, Univ. of Rochester17 Baker 1981 D2 Q2<0.3 Region, Interest 1.Determine Ma=radius of axial proton 2. Compare to Ma from pion electroproduction 3. Determine quaielastic cross section where most of the events are - for neutrino oscillation in the 1 GeV region, e.g. K2K,JHF MiniBoone. 4.Sensitive to both Pauli Exclusion and final state ID if a nuclear target is used, e.g. Carbon, Water. Lose Quasielastic events, or misID resonance events. -> - Need to use Jlab Hall B data on D2, C and Fe - Manly Analysis proposal 5.Low recoil proton momentum P=Sqrt(Q2) Q2 > 1 GeV2 Region, Interest 1.Determine deviations from Dipole form factors is it like Gep or Gmp. 2.Not sensitive to Paul Exclusion, but sensitive to final state ID. -> - Need to use Jlab Hall B data on D2, C and Fe - Manly analysis proposal 3.Higher recoil proton momentum P=Sqrt(Q2) Pauli effect on C12, Q2<0.3 GeV2

Arie Bodek, Univ. of Rochester18 Type in their d  /dQ2 histogram. Fit with our best Knowledge of their parameters : Get M A = (A different central value, but they do event likelihood fit And we do not have their the event, just the histogram. If we put is best knowledge of form factors, then we get M A = or  M A = So all their Values for M A. should be reduced by Experiment 1

Arie Bodek, Univ. of Rochester19 Using these data we get  M A to update to for latest ga+form factors. (note different experiments have different neutrino energy Spectra, different fit region, different targets, so each experiment requires its own study). A Pure Dipole analysis, with ga=1.23 (Shape analysis) - if redone with best know form factors -->  M A = (I.e. results need to be reduced by 0.047) for different experiments can get  M A from to Miller did not use pure dipole (but did use Gen=0)

Arie Bodek, Univ. of Rochester20 Redo Baker 81 analysis D2: They quote M A =1.07 We get with their assumptions M A = > Agree Best Form Factors versus What they used [(Olsson) and Gen=0] Gives  M A = Best form factors versus [ pure Dipole and Gen=0] Gives Gives  M A = Experiment 2

Arie Bodek, Univ. of Rochester21 D2: Kitagaki paper gets Ma= When we fit the Q2 spectra with their assumptions (Ollson) we get Difference between using Their assumptions and best Form factors and ga is that the Answer will be changed by (smaller) Difference between the Dipole form factors and the best form factors for this data is Experiment 3

Hep-ph/ (2001) For updated M A expt. need to be reanalyzed with new g A, and G E N Probably more correct to use =M A Difference In Ma between Electroproduction And neutrino Is understood M A from neutrino expt. No theory corrections needed 1.11=M A =M A average From Neutrino quasielastic From charged Pion electroproduction

Arie Bodek, Univ. of Rochester23 Will go up to = With Bodek/Budd/Arrington Form factors Versus theory =0.055

Arie Bodek, Univ. of Rochester24 Reanalysis of

Arie Bodek, Univ. of Rochester25 Typo In LS paper 2

Arie Bodek, Univ. of Rochester26 P of proton is close to Sqrt (Q2), Energy transfer is small, so q = q3 q3= P3 of proton, Energy of proton = Q2/2M For Q2=0.25 GeV2 q3 =P3=0.5 GeV Proton Kinetic Energy = 0.12 GeV = 120 MeV For Q2=0.11 GeV2, q3=P3=0.33 GeV Proton kinetic energy = 55 MeV Typo In LS paper 2

Arie Bodek, Univ. of Rochester GeV P = 15 cm of scintillator = 120 MeV energy Versus 1 mip = 2 MeV/cm. Get 60 mips For Q2=0.110 GeV2, q3=P=0.330 GeV Proton kinetic energy = P**2/2M = 55 MeV Range about 5 cm - Note nuclear binding about 30 MeV Back of envelope estimates - needs to be done more quantitatively

Arie Bodek, Univ. of Rochester28 Baker 1981 D2 Q2<0.3 Region, Interest 1.Determine Ma=radius of axial proton 2. Compare to Ma from pion electroproduction 3. Determine quaielastic cross section where most of the events are - for neutrino oscillation in the 1 GeV region, e.g. K2K,JHF MiniBoone. 4.Sensitive to both Pauli Exclusion and final state ID if a nuclear target is used, e.g. Carbon, Water. Lose Quasielastic events, or misID resonance events. -> - Need to use Jlab Hall B data on D2, C and Fe - Manly Analysis proposal 5.Low recoil proton momentum P=Sqrt(Q2) Q2 > 1 GeV2 Region, Interest 1.Determine deviations from Dipole form factors is it like Gep or Gmp. 2.Not sensitive to Paul Exclusion, but sensitive to final state ID. -> - Need to use Jlab Hall B data on D2, C and Fe - Manly analysis proposal 3.Higher recoil proton momentum P=Sqrt(Q2) Pauli effect on C12, Q2<0.3 GeV2

Arie Bodek, Univ. of Rochester29 Q2<0.3 Region, Interest 1.Determine Ma=radius of axial proton 2. Compare to Ma from pion electroproduction 3. Determine quaielastic cross section where most of the events are - for neutrino oscillation in the 1 GeV region, e.g. K2K,JHF MiniBoone. 4.Sensitive to both Pauli Exclusion and final state ID if a nuclear target is used, e.g. Carbon, Water. Lose Quasielastic events, or misID resonance events. -> - Need to use Jlab Hall B data on D2, C and Fe - Manly Analysis proposal 5.Low recoil proton momentum P=Sqrt(Q2) Q2 > 1 GeV2 Region, Interest 1.Determine deviations from Dipole form factors is it like Gep or Gmp. 2.Not sensitive to Paul Exclusion, but sensitive to final state ID. -> - Need to use Jlab Hall B data on D2, C and Fe - Manly analysis proposal 3.Higher recoil proton momentum P=Sqrt(Q2)

Arie Bodek, Univ. of Rochester30 Slide 16 Double exponential measured Two components m and 3.2 m Need to know strip Uniformity well. Energy resolution Depends on Npe. Double sided readout helps match x, y. One fiber Read on both sides One side with mirror Two fibers with mirrors

Arie Bodek, Univ. of Rochester31 Slide 16 One fiber Read on both sides One side with mirror Two fibers with mirrors 1.2 mm 3.9 Lambda 1 = 10 PE With 10% QE So actually 100 Photons 1cm thick 4.1 cm wide strip

Arie Bodek, Univ. of Rochester32

Arie Bodek, Univ. of Rochester33 Note that higher ME is from quasideuteron contribution: From 1998 article of 1.94 GeV beam In Russia YF 61, 256 (1998). Translation Physic of Atomic Nuclei, 61, 207 (1998).Multiple scattering is not the explanation

Arie Bodek, Univ. of Rochester34

Arie Bodek, Univ. of Rochester35 Reasons for Doubles sided readout A.If both sides read for every channel - e.g. CCD readout (all events in a pulse) 1.Better understanding of how to correct for channel to channel attenuation lengths and calibration 2.Better resolution - more light 3.Monitor time dependence of attenuation length 4.Resolve left X, Y ambiguity in each bar. - helps resolve multiple events in a spill B.Option possible - if we wish to do timing instead. 1.Sum up 100 fibers into a single 2” NuTeV phototube 2.10,000 channels become 100 channel 3Put fast timing readout on these 100 channels.- timing for K+ decay, separate several events in same spill. 4.Can use for triggering CCD’s if needed. C.Overall philosophy - better segmentation, better resolution, are more important then more mass or more statistics --> double side readout - If less mass is an outcome, - > fewer events per spill

Arie Bodek, Univ. of Rochester36 From SLAC library- Physics of Atomic Nuclei -- July Volume 60, Issue 7, pp Effect of nuclear matter on electron–nucleon interaction in the reaction 12C(e,e[prime]p) K. V. Alanakyan, M. J. Amaryan, G. A. Asryan, R. A. Demirchyan, K. Sh. Egiyan, O. K. Egiyan, M. S. Ohandjanyan, M. M. Sargsyan, Yu. G. Sharabyan, and S. G. Stepanyan Yerevan Physics Institute, ul. Brat'ev Alikhanian 2, Yerevan, Republic of Armenia (Received July 25, 1996; revised November 19, 1996) Experimental data on quasielastic electron scattering by carbon nuclei in the reaction (e,e[prime]p) are presented for incident-electron energies of 1.6 and 2.06 GeV, the electron scattering angles being 19.5° and 14.2°, respectively. Recoil protons are detected in the momentum range between 420 and 640 MeV/c. Owing to the chosen kinematical conditions, information about the interaction of electrons with a bound proton can be deduced from analysis based on the plane-wave impulse approximation. The results are compared with predictions of theoretical models. ©1997 ] Physics of Atomic Nuclei -- February Volume 61, Issue 2, pp Emission of cumulative protons in the reaction 12C(e,e[prime]p) K. V. Alanakyan, M. J. Amaryan, G. A. Asryan, R. A. Demirchyan, K. Sh. Egiyan, M. S. Ohanjanyan, M. M. Sargsyan, S. G. Stepanyan, and Yu. G. Sharabyan Yerevan Physics Institute, ul. Brat'ev Alikhanian 2, Yerevan, Armenia (Received November 19, 1996) The emission of cumulative protons in the reaction 12C(e,e[prime]p)leading to the complete fragmentation of the target nucleus is investigated for the first time. A detector was exposed to a 1.94-GeV electron beam extracted from the Yerevan synchrotron. The spectra of electrons scattered at an angle of 15° and detected in coincidence with a cumulative proton are explored for proton kinetic energies in the range Tp = 82–198 MeV and for proton emission angles 66°–140°. The energy spectra of protons for various values of energy transfer to the nucleus are also studied. Experimental data are compared with theoretical predictions that are based on the model of short-range nucleon–nucleon correlations and which take into account secondary processes (such as the excitation of the Delta isobar). The majority of product cumulative protons appear to originate from two-nucleon correlations, and less than 20 of them are associated with secondary mechanisms. ©1998