(Yamagata University) for COMPASS++/AMBER working group Proton radius measurements with a high energy muon beam in the future CERN experiment Firstly, I’d like to thank the organizers for inviting me to give a talk. The title of my talk is “Experimental study with lepton scattering.” I’ll review the recent progress in the study of the nucleon structure in lepton scattering experiments. Takahiro Iwata, (Yamagata University) for COMPASS++/AMBER working group Workshop, 2019/3/20-21, 25-30, ELPH Tohoku University

OUTLINE Introduction: Proton radius puzzle COMPASS at CERN COMPASS++/AMBER Plans for proton radius measurement Experimental challenges Proposed set-up 2018 test measurements This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Proton radius puzzle This is the outline of my talk. The values for the proton charge radius measured with electrons(ep & hydrogen) : 0.8751 ±0.0061 fm muons (muonic hydrogen) : 0.8409 ±0.0004 fm This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies arXiv:1706.00696 Is it related to the violation of universality between electron and muon? The missing piece is the muon scattering. Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Elastic electron(muon)-proton scattering This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Experimental method This is the outline of my talk. precise measurement of GE(Q2) in the rage of Q2 as small as possible extrapolation towards zero  slope at Q2=0 This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies recent MAMI results Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

New experiments This is the outline of my talk. electrons ( GeV region, single arm): MAMI, Jlab electrons ( GeV region, proton recoil): MAMI/GSI/PNPI using active target electrons ( 20-60 MeV ): ELPH low energy muons (100-200 MeV): MUSE@PSI New idea  high energy muons (50-200 GeV) This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Advantages of high-energy m beam much reduced radiative corrections compared to electrons This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies much smaller Coulomb corrections compared to low energy muons correction depending on scattering angle small scattering angle at higher energies Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

COMPASS at CERN - Here is the recent result for the Collins Asymmetry obtained for proton target, for positive and negative pions. What we can see here is non-zero signal is clearly visible.   Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

COmmon Muon Proton Apparatus for Structure and Spectroscopy COMPASS COmmon Muon Proton Apparatus for Structure and Spectroscopy About 230 physicists from 13 countries To study hadron structure and spectroscopy Using the secondary beam from SPS at CERN With the versatile common spectrometer COMPASS is the similar experiment, which is currently running at CERN. using high energy polarized muon beam with the energy up to 200GeV and the polarized solid target. Thanks to the multi-purpose spectrometer, SI-DIS events are also measured. Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

COMPASS at CERN COMPASS is the similar experiment, which is currently running at CERN. using high energy polarized muon beam with the energy up to 200GeV and the polarized solid target. Thanks to the multi-purpose spectrometer, SI-DIS events are also measured. Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

The M2 beam line for COMPASS Hadron absorber (only for m beam) Beryllium target p (400 GeV) p, K, p naturally polarized m+/-(<200 GeV) hadrons+/- (< 200GeV) SPS Secondary particles p / p dominant ~600m decay pipe positive muon case This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies components of the hadron beam NIM A779(2015)69-115 NIM A577(2007) 455-518 NB: hadrons can be tagged by a differential Cherenkov counter installed in the beam line NB:　nominal spill 4.8s within a 16.8 s long SPS cycle ＝＞　instantaneous muon flux : 4x107/s Takahiro IWATA, Nucleon Structure, 2019, 2, 20-21, Sagae, Yamagata, Japan

Setup for muon program DIS & SI-DIS setup Straws SDC MWPC W45 DIS & SI-DIS setup with muon beam & polarized target SciFi Silicon Micromegas GEMs MuonWall Polarised Target (NH3 for p, 6LiD for d) COMPASS is the similar experiment, which is currently running at CERN. using high energy polarized muon beam with the energy up to 200GeV and the polarized solid target. Thanks to the multi-purpose spectrometer, SI-DIS events are also measured. E/HCAL E/HCAL SM1 SM2 MuonWall Pol. beam fom SPS 160-200 GeV, pol. = 80% RICH two stage spectrometer tracking, calorimetry, PID Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Setup for muon program in detail COMPASS is the similar experiment, which is currently running at CERN. using high energy polarized muon beam with the energy up to 200GeV and the polarized solid target. Thanks to the multi-purpose spectrometer, SI-DIS events are also measured. Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Data taking 2002 - 2021 2002 muon program with 160 GeV pol. muon d↑ p↑ 2002-06 6LiD pol. target (d) L-mode: 80 / T-mode: 20 2005 no data taking 2007 NH3 pol. target (p) 160 GeV pol. muon L: 50 / T: 50 2008, 09 hadron program with p/p/K beam at 190 GeV 2010 NH3 pol. target (p/T-mode) 160 GeV pol. muon 2011 NH3 pol. target (p/L-mode) 200 GeV pol. muon 2012 hadron program & GPD pilot run 2013 GPD-program with muon beam & LH2 target 2014 DY-pilot run 2015 DY prog. with NH3 pol. target (p/T-mode) 190 GeV pion(-) 2016 GPD-program with muon beam & LH2 target 2017 GPD-program with muon beam & LH2 target 2018 DY prog. with NH3 pol. target (p/T-mode) 190 GeV pion(-) 2021 muon program with 160 GeV pol. muon with LiD pol. target END of COMPASS d↑ p↑ p↑ p↑ punpol p↑ d↑ Takahiro IWATA JPS meeting, 2019, March. 14-17, Kyushu University

“A new QCD facility at the M2 beam line of the CERN SPS” COMPASS++/AMBER “A new QCD facility at the M2 beam line of the CERN SPS” Letter of intent : arXiv:1808.00848v3 [hep-ex] 15 Oct 2018 Proposal to be submitted in 2019 Proton radius measurement with a muon beam hadron physics with standard muon and hadron beams hadron physics with RF-separated hadron beams Here is the recent result for the Collins Asymmetry obtained for proton target, for positive and negative pions. What we can see here is non-zero signal is clearly visible.   Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Plans for the proton radius measurement - Here is the recent result for the Collins Asymmetry obtained for proton target, for positive and negative pions. What we can see here is non-zero signal is clearly visible.   Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Elastic muon-proton scattering measurement scattering of high energy muons off proton target measurement of Q2 dependence of elastic cross section no GE-GM separation possible at high energies  GE2+tGM2 measured At small values of Q2(i.e. small t) of interest, contribution from GM is small experimental challenges : identify elastic reaction at very low Q2 very small scattering angles( ～ 100 m rad) and energy same as incoming energy low energy recoil proton with angles of about 90 degree experimental requirements detection of muon with very low scattering angles muons at scattering angle > 100 m rad (10-4 (GeV/c)2 ) are selected muons at scattering angle < 5 mrad (99% ) are vetoed to suppress triggers detection of recoil proton with low energy active proton TPC target mandatory at least for low Q2 < 0.02 (GeV/c)2 SciFi detector inside TPC volume for higher Q2> 0.02 (GeV/c)2 This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Proposed setup This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies hydrogen TPC as active target silicon telescopes　with resolution < 10um up- and downstream of target muon ID provided by the spectrometer trigger on recoil proton and kink in muon track Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Active hydrogen TPC target This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies high pressure hydrogen TPC developed by PNPI (Gat china) measurement of recoil proton energy ( resolution 60keV) necessary rage from 0.5 MeV to 100 MeV (Q2>10-4 (GeV/c)2) use different pressure from 4 to 20 bar Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

SciFi detector in TPC volume At higher Q2( > 0.02 (GeV/c)2), recoiling protons do not stop in TPC SciFi detector installed in gas volume of TPC inner layers : 2 mm x 2mm outer layers: 4 mm x 4mm to 8 mm x 8 mm dE/dx, E analysis available energy resolution of a few % up　to 100 MeV stereo angle of 6 degree for 3D information readout by SiPM( Hamamatsu S13360-3025 or KETEK PM3325) This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Goal of measurement This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies assuming one year of data taking (at least 2x106 muons/s ) measurement between 10-3(GeV/c)2 < Q2 < 0.1(GeV/c)2 TPC :10-3 < Q2 < 0.02(GeV/c)2 SciFi : 0.02 < Q2 < 0.1(GeV/c)2 Q2 resolution : DQ2 =1.4x10-4 (GeV/c)2 goal : uncertainty of √　<rE2> is 0.01 fm Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

TPC test with muon beam in 2018 This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies Study TPC performance with the muon beam TPC between 4 tracking stations downstream COMPASS-DY setup Tracking via Si microstrip detectors ( Dx ~ 10 um) Muon beam : Em= 190 GeV, sxxsy=81x84 mm, up to 2 MHz Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Test setup in 2018 This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies Trigger scintillators (BT) 64x48 mm x3 Si microstrip detectors (SI) 70 x 40 mm x 4(XY) Short baseline (~4m) limits Q2~ 3x10-3 (GeV/c)2 TPC as active target with D=200 mm Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

TPC structure This is the outline of my talk. sensitive region This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies Gas: H2 Pressure: p=1,4,8 bar LCG=220 mm VC=18 kV, VG=1 kV tCG ~ 60 us Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Preliminary results This is the outline of my talk. reconstructed vertices from silicon telescope tracks This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies z-cut: +24cm > z > +45 cm (active region) only tracks pass through TPC windows z-resolution about 3 cm Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Preliminary results This is the outline of my talk. time difference: SI – TPC width: 60 us = drift time This is the outline of my talk. Following a brief introduction. I’ll talk about these topics; Longitudinal Spin Structure Transverse Spin Effects GPD Studies C.Dreisback, COMPASS collaboration meeting (15.11.2018) Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Timelines Here is the recent result for the Collins Asymmetry proton radius measurement ? NOW Here is the recent result for the Collins Asymmetry obtained for proton target, for positive and negative pions. What we can see here is non-zero signal is clearly visible.   Long-term plan by new collaboration COMPASS++/AMBER Short-term plan by COMPASS Takahiro IWATA, Nucleon Structure, 2019, 2, 20-21, Sagae, Yamagata, Japan

Summary Measurement in muon proton elastic scattering is a missing piece in order to solve the proton radius puzzle A measurement with a high energy muon beam at CERN M2 beam line is proposed by the COMPASS++/AMBER. The high energy muon beam gives advantages from the point of view of radiative correction and Coulomb correction. Required active hydrogen TPC target is under development with the muon beam at CERN. The measurement is expected to be done in 2022. Now, let me conclude my talk. Significant progress in the study　with lepton scattering was achieved Du and Dd are well determined Polarized sea distributions are small Gluon polarization is compatible with 0 in the measured range Transversity and Sivers PDF have been extracted The asymmetry on un-polarized nucleon gives a hint of BM PDF Wealth of GPD data were accumulated by HERMES and Jlab-experiments Exciting GPD programs at COMPASS-II and JLab-12GeV are planned   Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University

Spares Firstly, I’d like to thank the organizers for inviting me to give a talk. The title of my talk is “Experimental study with lepton scattering.” I’ll review the recent progress in the study of the nucleon structure in lepton scattering experiments. Hadron China 2017, 24-28, 2017, Nanjing

Scattering angle v.s. Q2 Here is the recent result for the Collins Asymmetry obtained for proton target, for positive and negative pions. What we can see here is non-zero signal is clearly visible.   Takahiro IWATA, workshop 2019 20-21, ELPH Tohoku University