Dept. of Phys., Kyushu Univ. Measurement of 2 H(p,pp)n cross sections at E p = 250 MeV Sho Kuroita 1, K. Sagara 1, Y. Eguchi 1, K. Yashima 1, T. Shishido 1, T. Yabe 1, M. Dozono 1, Y. Yamada 1, T. Wakasa 1, T. Noro 1, H. Matsubara 2 J. Zenihiro 2, A. Tamii 2, H. Okamura 2, K. Hatanaka 2, T. Saito 3 Y. Maeda 3, H. Kamada 4, Y. Tameshige 5 1: Department of Physics, Kyushu University 2: Research Center for Nuclear Physics (RCNP), Osaka University 3: Department of Applied Physics, University of Miyazaki 4; Department of Physics, Faculty of Engineering, Kyushu Institute of Technology 5: National Institute of Radiological Sciences

Dept. of Phys., Kyushu Univ Fujita – Miyazawa suggested the existence of three nucleon force. Then 2  -exchange three nucleon force (2  3NF) models were created, and these 2  3NF well described binding energies of nuclei were constructed by few nucleon. Differential cross sections of pd scattering below E N = 140 MeV were well described by including 2  3NF in Faddeev calculations. 2009/9/32 FB19 - Bonn University, Germany Cross sections of pd elastic scattering at E p = 65, 140 MeV NN + TM3NF NN only H. Witala et al., PRL81 (1998) MeV 140 MeV

Dept. of Phys., Kyushu Univ. Besides 2  -exchange 3NF, heavy- meson exchange 3NF are predicted in  PT. These heavy-meson exchange 3NFs are expected that the effects become larger at high energy region. 2009/9/33 FB19 - Bonn University, Germany

Dept. of Phys., Kyushu Univ. Above E N = 140 MeV, cross section of pd elastic scattering does not described by Faddeev calculation with 2π3NF. 2009/9/34 FB19 - Bonn University, Germany E N = 250 MeV Nd elastic scattering K. Hatanaka et al., PRC (2002). Y. Maeda et al., PRC (2007). NN + TM3NF NN only ＊ The disagreement of pd elastic scattering become larger at higher incident energy. ＊ And the disagreements are not related to π-threshold  -threshold

Dept. of Phys., Kyushu Univ. So we have measured cross section of pd breakup reaction in order to investigate origins of the disagreement on Nd scattering cross section. We measured cross section and analyzing power A y of inclusive pd breakup 2 H(p,p)pn reaction at E p = 247 MeV to study the global feature of pd breakup reaction at intermediate energy region. 2009/9/35 FB19 - Bonn University, Germany At intermediate energies, Nd breakup reaction is main reaction process in 3N systems. J. Kuros-Zoluierczuk et al.,PRC66, (2002). Observable : cross section, A y (E = 70 ~ 230 MeV) Angle : 10, 15, 20 deg. Detector : Spectrometer VDC, Scintillator Target : Liquid Deuterium Calc. by H. Witala, private communication detected p1 Angle is free !

Dept. of Phys., Kyushu Univ. 2009/9/36 FB19 - Bonn University, Germany nd calculation by Prof. H. Witala Even after inclusion of 2π3NF, large disagreements remain. The experimental cross section is about 1.8 times larger than calc. at 15 deg. First, we pay attention to only the disagreement of cross sections.

Dept. of Phys., Kyushu Univ. 2009/9/37 FB19 - Bonn University, Germany pd calculation by A. Deltuva pd calculation indicate Coulomb effect slightly decreases cross section. To sum up, the orign(s) of the disagreement is not Coulomb effcet.

Dept. of Phys., Kyushu Univ. 2 H(p,p 1 )pn reaction == previous experiment == 2 H(p,p 1 p 2 )n reaction == New experiment == 2009/9/38 FB19 - Bonn University, Germany detected p1 Angle is free !  1 = 15°fixed E 1 = 150 MeV 22

Dept. of Phys., Kyushu Univ. Dependence of cross section for  2 d 3  /d  1 d  2 dE(15 f, 150 MeV,  2, 180 f ) 3N calculation for 2 H(p,p 1 p 2 )n reaction at 250 MeV suggests that 2 H(p,pp)n cross section has the maximum at  2 ~ 35 deg. Dependence of cross section for   d 3  /d  1 d  2 dE(15 f, 150 MeV,  f,  12 ) Also 3N calculation suggests that 2 H(p,p 1 p 2 )n cross section has the maximum at  12 = 180 deg. So we measure cross section at  12 = 180 deg. 2009/9/39 FB19 - Bonn University, Germany Calc. by Prof. H. Kamada 2 2  12

Dept. of Phys., Kyushu Univ. 2 H(p,pp)n breakup reactions at E p = 250 MeV 250 MeV proton beam from RING RCNP WS course in West exp. Room Observable : Cross section target : Liquid deuterium CD 2 Detector : GR (spectrometer) LAS (spectrometer) Scintillator Luminosity monitor dp elastic scattering (kinematical coincidence) Configuration 2 H(p,p 1 p 2 )n reaction  1 (GR) = 15 deg fixed  2 (LAS) = 35, 50, 65, 80 deg 2009/9/310 FB19 - Bonn University, Germany Scatt. Chamber * Liq. D 2 GR LAS

Dept. of Phys., Kyushu Univ. We used liquid deuterium target system as deuteron target. Liquid deuterium target is an almost pure and very thick deuteron target, and it enables low background experiments. Thickness: ~ 220 mg/cm 2, (target length = ~12 mm) Cell temperature : ~ 18 K (cooled by Cryo – refrigerator) (monitored by Si diode thermometer) The thickness of liquid deuterium (liq. D 2 ) target is varied by condition of cell temperature and gas pressure e.t.c.. So we monitored the thickness by using coincidence measurement of pd elastic scattering simultaneously. 2009/9/311 FB19 - Bonn University, Germany Liq. D 2 target cell expand ! Cryo - refrigerator Heater

Dept. of Phys., Kyushu Univ. We have measured cross sections of 2 H(p,p 1 )pn reaction to check the disagreement of the previous 2 H(p,p)pn cross sections at 250 MeV in the same setup. We have reconfirmed the large disagreement of 2 H(p,p 1 )pn cross section between experimental data and Faddeev calculation including 2  3NF. 2009/9/312 FB19 - Bonn University, Germany expand preliminary Calc. by Prof. H. Witala

Dept. of Phys., Kyushu Univ.   (GR) = 15 deg,  2 (LAS) = 35 deg,  12 = 180 deg. 2009/9/313 FB19 - Bonn University, Germany  1 momentum True + B.G. event B.G. event B.G. subtract E 1 [MeV]

Dept. of Phys., Kyushu Univ. 2009/9/314 FB19 - Bonn University, Germany  1 =15deg, E 1 =150 MeV  2 =50 deg  2 =35 deg preliminary Calc. by Prof. H. Kamada

Dept. of Phys., Kyushu Univ. 2009/9/315 FB19 - Bonn University, Germany  1 =15deg, E 1 =150 MeV  2 =80 deg  2 =65 deg preliminary Calc. by Prof. H. Kamada

Dept. of Phys., Kyushu Univ. Dependence of cross section for  2 d 3  /d  1 d  2 dE(15 f, 150 MeV,  2, 180 f ) The cross sections of 2 H(p,p 1 p 2 )n reaction at 250 MeV have the maximum at  2 = 35 deg. The ratio of the disagreement of 2 H(p,p 1 p 2 )n cross section have also has the maximum at  2 = 35 deg. And the ration become smaller at backward angles. 2009/9/316 FB19 - Bonn University, Germany preliminary Calc. by Prof. H. Kamada 16  1 = 15°fixed E 1 = 150 MeV  2 = 35°,50°, 65°,80°

Dept. of Phys., Kyushu Univ. 2009/9/317 FB19 - Bonn University, Germany  1 =15deg, E 1 =150 MeV  2 =50 deg  2 =35 deg preliminary Calc. by Prof. H. Kamada

Dept. of Phys., Kyushu Univ. We have measured cross sections of 2 H(p,p 1 p 2 )n reaction at E 1 = 150 MeV,  1 = 15 deg fixed,  2 = 35, 50, 65, 80 deg. (total 4 setup). Simultaneously, we have measured cross section 2 H(p,p)pn reaction and confirmed the large disagreement between experimental data and Faddeev calculations including 2  3NF. The preliminary result of 2 H(p,pp)n cross sections suggest large disagreements between experimental data and calculations as same as 2 H(p,p)pn reaction. We think that origin(s) of these discrepancy is Heavy-meson exchange 3NF  3NF,  3NF, e.g.. Relativistic effect So we will have to study relations between these disagreement and candidate of origin(s). 2009/9/318 FB19 - Bonn University, Germany preliminary ~ x 1.8

Dept. of Phys., Kyushu Univ. Nd elastic scattering ( , A y, K ij ) … RCNP, RIKEN, KVI etc (E N > 140 MeV) pd radiative capture (  ?, A ij ) … RCNP (E d = 200 MeV) 2009/9/319 FB19 - Bonn University, Germany

Dept. of Phys., Kyushu Univ. The disagreements of cross sections for 2 H(p,p 1 )pn at 250 MeV become larger at forward angles. Dose the disagreements vanish at backward angle ? 2009/9/320 FB19 - Bonn University, Germany detected p Previous exp. 2 H(p,p 1 )pn reaction So we have also measured cross sections of 2H(p,p)pn reaction at backward angles to see whether the discrepancy exist at backward angles.

Dept. of Phys., Kyushu Univ. Why d 3  /d  1 d  2 dE(15 f, 150 MeV, ~  f, 180 f ) has a maximum ? When  1 = 15 deg and E 1 = 150 MeV,  2 =36 deg, 2 H(p,p 1 p 2 )n reaction is in “Collinear configuration”. 3N calculations predict cross section has maximum at Collinear configuration. Whether SR3NF effects dominate in collinear configuration or not is also an interesting subject ? 2009/9/321 FB19 - Bonn University, Germany  1 = 15 deg (lab.) E 1 = 150 MeV

Dept. of Phys., Kyushu Univ. So we have measured cross section of pd breakup reaction in order to investigate origins of the disagreement on Nd scattering cross section. We measured cross section and analyzing power A y of inclusive pd breakup 2 H(p,p)pn reaction at E p = 247 MeV to study the global feature of pd breakup reaction at intermediate energy region. 2009/9/322 FB19 - Bonn University, Germany At intermediate energies, Nd breakup reaction is main reaction process in 3N systems. J. Kuros-Zoluierczuk et al.,PRC66, (2002). Observable : cross section, A y (E = 70 ~ 230 MeV) Angle : 10, 15, 20 deg. Detector : Spectrometer VDC, Scintillator Target : Liquid Deuterium Calc. by H. Witala, private communication measured

Dept. of Phys., Kyushu Univ. So we maybe think that the strength / effects of 2  3NF are also understood by studies of binding energies of nuclei were constructed by few-nucleon and Nd elastic scattering. But others of three-nucleon (3NF) is not found, for example,  3NF,  3NF that were the existence expected. Effects of these 3NF may be found at higher energies because these 3NF are the model exchange heavier than  Besides 2p3-exchange NF, heavy-meson exchange 3NF are redicted in  PT /9/323 FB19 - Bonn University, Germany

Dept. of Phys., Kyushu Univ. The disagreement of cross section exist at another energies, for example, 2 H(p,n) reaction at E p = 197 MeV by IUCF. We have already systematic cross section data for 2 H(p,p)pn reaction at 250 MeV in wide energy region of reaction protons. If we would performed a experiment for 2 H(p,pp)n reaction, we should measure cross section for 2 H(p,p)pn to get information of global feature and pp-FSI. 2009/9/324 FB19 - Bonn University, Germany Cross section of 2 H(p,n) at IUCF D.L. Prout et al., PRC (2002). In this experiment, cross sections for 2 H(p,n) was measured at  = 13, 24, 37, 48 deg, and concentrated to QFS. expand

Dept. of Phys., Kyushu Univ. The discrepancy of 2 H(p,p 1 )pn is the largest at around E 1 = 150 MeV. So we have measured cross sections for 2 H(p,p 1 p 2 )n reaction around E 1 = 150 MeV at fixed  1 = 15 deg. in order to investigation origins for the disagreement of 2 H(p,p 1 )pn. 2009/9/325 FB19 - Bonn University, Germany  1 = 15°fixed E 1 = 150 MeV 22 New exp. 2 H(p,p 1 p 2 )n reaction (microscopic study) Previous exp. 2 H(p,p 1 )pn reaction detected p1 Angle is free !