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S Uehara - One of the best experts on this subject based on the ideXlab platform.
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study of pi 0 pair production in single tag two photon collisions
Physical Review D, 2016Co-Authors: M Masuda, S Uehara, Y Watanabe, H Nakazawa, A Abdesselam, I Adachi, H Aihara, Al S Said, D M Asner, H AtmacanAbstract:We report a measurement of the differential cross section of pi(0) pair production in single-tag two-photon collisions, gamma*gamma -> pi(0) pi(0), in e(+) e(-) scattering. The cross section is measured for Q(2) up to 30 GeV2, where Q(2) is the negative of the invariant mass squared of the tagged photon, in the kinematic range 0.5 GeV < W < 2.1 GeV and vertical bar cos theta*vertical bar < 1.0 for the total energy and pion scattering angle, respectively, in the gamma*gamma Center-of-Mass System. The results are based on a data sample of 759 fb(-1) collected with the Belle detector at the KEKB asymmetric-energy e(+) e(-) collider. The transition form factor of the f(0)(980) and that of the f(2)(1270) with the helicity-0, -1, and -2 components separately are measured for the first time and are compared with theoretical calculations.
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high statistics study of ηπ0 production in two photon collisions
Physical Review D, 2009Co-Authors: S Uehara, Y Watanabe, H Nakazawa, I Adachi, H Aihara, K Arinstein, V Aulchenko, A M BakichAbstract:The differential cross section for the process γγ→η π0 has been measured in the kinematic range 0.84GeV
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high statistics study of eta pi0 production in two photon collisions
Physical Review D, 2009Co-Authors: S Uehara, D Liventsev, B R Ko, Z P Zhang, D Epifanov, H Kichimi, C P Shen, V Zhilich, J Crnkovic, K HayasakaAbstract:The differential cross section for the process {gamma}{gamma}{yields}{eta}{pi}{sup 0} has been measured in the kinematic range 0.84 GeV
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high statistics study of boldmath eta pi 0 production in two photon collisions
Physical Review D, 2009Co-Authors: S UeharaAbstract:The differential cross section for the process $\gamma \gamma \to \eta \pi^0$ has been measured in the kinematic range $0.84 \GeV < W < 4.0 \GeV$, $|\cos \theta^*|<0.8$, where $W$ and $\theta^*$ are the energy and $\pi^0$ (or $\eta$) scattering angle, respectively, in the $\gamma\gamma$ Center-of-Mass System. The results are based on a 223 fb$^{-1}$ data sample collected with the Belle detector at the KEKB $e^+ e^-$ collider. Clear peaks due to the $a_0(980)$ and $a_2(1320)$ are visible. The differential cross sections are fitted in the energy region $0.9 \GeV < W < 1.46 \GeV$ to obtain the parameters of the $a_0(980)$. Its mass, width and $\Gamma_{\gamma \gamma} \B (\eta \pi^0)$ are measured to be $982.3 ^{+0.6}_{-0.7} ^{+3.1}_{-4.7} \MeV/c^2$, $75.6 \pm 1.6 ^{+17.4}_{-10.0} \MeV$ and $128 ^{+3}_{-2} ^{+502}_{-43} \eV$, respectively. The energy and angular dependences above 3.1 GeV are compared with those measured in the $\pi^0 \pi^0$ channel. The integrated cross section over $|\cos \theta^*|<0.8$ has a $W^{-n}$ dependence with $n = 10.5 \pm 1.2 \pm 0.5$, which is slightly larger than that for $\pi^0 \pi^0$. The differential cross sections show a $\sin^{-4} \theta^*$ dependence similar to $\gamma \gamma \to \pi^0 \pi^0$. The measured cross section ratio, $\sigma(\eta \pi^0)/\sigma(\pi^0 \pi^0) = 0.48 \pm 0.05 \pm 0.04$, is consistent with a QCD-based prediction.
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high statistics study of neutral pion pair production in two photon collisions
Physical Review D, 2009Co-Authors: S Uehara, Y Watanabe, H Nakazawa, H Aihara, K Arinstein, V Aulchenko, A M Bakich, E L Barberio, K Belous, V BhardwajAbstract:The differential cross sections for the process gamma gamma -> pi(0)pi(0) have been measured in the kinematic range 0.6 GeV < W < 4.1 GeV, vertical bar cos theta* vertical bar < 0.8 in energy and pion scattering angle, respectively, in the gamma gamma Center-of-Mass System. The results are based on a 223 fb(-1) data sample collected with the Belle detector at the KEKB e(+)e(-) collider. The differential cross sections are fitted in the energy region 1.7 GeV < W < 2.5 GeV to confirm the two-photon production of two pions in the G wave. In the higher-energy region, we observe production of the chi(c0) charmonium state and obtain the product of its two-photon decay width and branching fraction to pi(0)pi(0). We also compare the observed angular dependence and ratios of cross sections for neutral-pion and charged-pion pair production to QCD models. The energy and angular dependence above 3.1 GeV are compatible with those measured in the pi(+)pi(-) channel, and in addition we find that the cross section ratio, sigma(pi(0)pi(0))/sigma(pi(+)pi(-)), is 0.32 +/- 0.03 +/- 0.05 on average in the 3.1-4.1 GeV region.
Atac H. - One of the best experts on this subject based on the ideXlab platform.
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Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4 GeV2≤Q2≤1 GeV2 EXCLUSIVE π0p ELECTROPRODUCTION off ⋯ N. MARKOV et al
'American Physical Society (APS)', 2020Co-Authors: Markov N., Joo K., Burkert V. D., Mokeev V., Smith L. C., Ungaro M., Adhikari S., Amaryan M. J., Angelini G., Atac H.Abstract:The exclusive electroproduction process ep→e′p′π0 was measured in the range of photon virtualities Q2=0.4-1.0GeV2 and the invariant mass range of the pπ0 System of W=1.1-1.8 GeV. These kinematics are covered in exclusive π0 electroproduction off the proton with nearly complete angular coverage in the pπ0 Center-of-Mass System and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σT+ϵσL,σLT, and σTT, were extracted via fitting the φπ0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N∗ and Δ∗ resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N∗ and Δ∗ resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the Nπ and π+π-p channels
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Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4GeV2 ≤ Q2 ≤ 1GeV2
'American Physical Society (APS)', 2020Co-Authors: Markov N., Joo K., Burkert V. D., Mokeev V., Smith L. C., Ungaro M., Adhikari S., Amaryan M. J., Angelini G., Atac H.Abstract:The exclusive electroproduction process ep→e′p′π0 was measured in the range of photon virtualities Q2=0.4–1.0GeV2 and the invariant mass range of the pπ0 System of W=1.1–1.8 GeV. These kinematics are covered in exclusive π0 electroproduction off the proton with nearly complete angular coverage in the pπ0 Center-of-Mass System and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σT+εσL,σLT, and σTT, were extracted via fitting the ϕπ0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N* and Δ* resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N* and Δ* resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the Nπ and π+π−p channels
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Exclusive ${\pi^{0}p}$ electroproduction off protons in the resonance region at photon virtualities 0.4 GeV${^{2}}$ ${\leq~ Q^{2} \leq~1}$ GeV${^{2}}$
'American Physical Society (APS)', 2020Co-Authors: Markov N., Joo K., Ungaro M., Adhikari S., Angelini G., Burkert V.d., Mokeev V.i., Smith L.c., Amaryan M.j., Atac H.Abstract:International audienceThe exclusive electroproduction process ep→e′p′π0 was measured in the range of photon virtualities Q2=0.4–1.0GeV2 and the invariant mass range of the pπ0 System of W=1.1–1.8 GeV. These kinematics are covered in exclusive π0 electroproduction off the proton with nearly complete angular coverage in the pπ0 Center-of-Mass System and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σT+εσL,σLT, and σTT, were extracted via fitting the ϕπ0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N* and Δ* resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N* and Δ* resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the Nπ and π+π−p channels
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Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4 GeV2≤Q2≤1 GeV2 EXCLUSIVE π0p ELECTROPRODUCTION off ⋯ N. MARKOV et al
'American Physical Society (APS)', 2020Co-Authors: Markov N., Joo K., Burkert V. D., Mokeev V., Smith L. C., Ungaro M., Adhikari S., Amaryan M. J., Angelini G., Atac H.Abstract:The exclusive electroproduction process ep\u2192e\u2032p\u2032\u3c00 was measured in the range of photon virtualities Q2=0.4-1.0GeV2 and the invariant mass range of the p\u3c00 System of W=1.1-1.8 GeV. These kinematics are covered in exclusive \u3c00 electroproduction off the proton with nearly complete angular coverage in the p\u3c00 Center-of-Mass System and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions \u3c3T+\u3f5\u3c3L,\u3c3LT, and \u3c3TT, were extracted via fitting the \u3c6\u3c00 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N 17 and \u394 17 resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N 17 and \u394 17 resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the N\u3c0 and \u3c0+\u3c0-p channels
Markov N. - One of the best experts on this subject based on the ideXlab platform.
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Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4 GeV2≤Q2≤1 GeV2 EXCLUSIVE π0p ELECTROPRODUCTION off ⋯ N. MARKOV et al
'American Physical Society (APS)', 2020Co-Authors: Markov N., Joo K., Burkert V. D., Mokeev V., Smith L. C., Ungaro M., Adhikari S., Amaryan M. J., Angelini G., Atac H.Abstract:The exclusive electroproduction process ep→e′p′π0 was measured in the range of photon virtualities Q2=0.4-1.0GeV2 and the invariant mass range of the pπ0 System of W=1.1-1.8 GeV. These kinematics are covered in exclusive π0 electroproduction off the proton with nearly complete angular coverage in the pπ0 Center-of-Mass System and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σT+ϵσL,σLT, and σTT, were extracted via fitting the φπ0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N∗ and Δ∗ resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N∗ and Δ∗ resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the Nπ and π+π-p channels
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Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4GeV2 ≤ Q2 ≤ 1GeV2
'American Physical Society (APS)', 2020Co-Authors: Markov N., Joo K., Burkert V. D., Mokeev V., Smith L. C., Ungaro M., Adhikari S., Amaryan M. J., Angelini G., Atac H.Abstract:The exclusive electroproduction process ep→e′p′π0 was measured in the range of photon virtualities Q2=0.4–1.0GeV2 and the invariant mass range of the pπ0 System of W=1.1–1.8 GeV. These kinematics are covered in exclusive π0 electroproduction off the proton with nearly complete angular coverage in the pπ0 Center-of-Mass System and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σT+εσL,σLT, and σTT, were extracted via fitting the ϕπ0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N* and Δ* resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N* and Δ* resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the Nπ and π+π−p channels
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Exclusive ${\pi^{0}p}$ electroproduction off protons in the resonance region at photon virtualities 0.4 GeV${^{2}}$ ${\leq~ Q^{2} \leq~1}$ GeV${^{2}}$
'American Physical Society (APS)', 2020Co-Authors: Markov N., Joo K., Ungaro M., Adhikari S., Angelini G., Burkert V.d., Mokeev V.i., Smith L.c., Amaryan M.j., Atac H.Abstract:International audienceThe exclusive electroproduction process ep→e′p′π0 was measured in the range of photon virtualities Q2=0.4–1.0GeV2 and the invariant mass range of the pπ0 System of W=1.1–1.8 GeV. These kinematics are covered in exclusive π0 electroproduction off the proton with nearly complete angular coverage in the pπ0 Center-of-Mass System and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σT+εσL,σLT, and σTT, were extracted via fitting the ϕπ0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N* and Δ* resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N* and Δ* resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the Nπ and π+π−p channels
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Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4 GeV2≤Q2≤1 GeV2 EXCLUSIVE π0p ELECTROPRODUCTION off ⋯ N. MARKOV et al
'American Physical Society (APS)', 2020Co-Authors: Markov N., Joo K., Burkert V. D., Mokeev V., Smith L. C., Ungaro M., Adhikari S., Amaryan M. J., Angelini G., Atac H.Abstract:The exclusive electroproduction process ep\u2192e\u2032p\u2032\u3c00 was measured in the range of photon virtualities Q2=0.4-1.0GeV2 and the invariant mass range of the p\u3c00 System of W=1.1-1.8 GeV. These kinematics are covered in exclusive \u3c00 electroproduction off the proton with nearly complete angular coverage in the p\u3c00 Center-of-Mass System and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions \u3c3T+\u3f5\u3c3L,\u3c3LT, and \u3c3TT, were extracted via fitting the \u3c6\u3c00 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N 17 and \u394 17 resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N 17 and \u394 17 resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the N\u3c0 and \u3c0+\u3c0-p channels
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Exclusive $\bm{\pi^{0}p}$ electroproduction off protons in the resonance region at photon virtualities 0.4~GeV$\bm{^{2}}$ $\bm{\leq~ Q^{2} \leq~1}$~GeV$\bm{^{2}}$
'American Physical Society (APS)', 2019Co-Authors: Markov N., Joo K., Burkert V. D., Mokeev V., Smith L. C., Ungaro M., Adhikari S., Angelini G., ~amaryan M. J., ~atac H.Abstract:The exclusive electroproduction process $ep \rightarrow e'p'\pi^{0}$ was measured in the range of photon virtualities $Q^{2} = 0.4 - 1.0$~GeV$^{2}$ and the invariant mass range of the $p\pi^{0}$ System of $W = 1.1 - 1.8$~GeV. These kinematics are covered in exclusive $\pi^{0}$ electroproduction off the proton with nearly complete angular coverage in the $p\pi^{0}$ Center-of-Mass System and with high statistical accuracy. Nearly 36000 cross section points were measured, and the structure functions $\sigma_T+\epsilon\sigma_L$, $\sigma_{LT}$, and $\sigma_{TT}$, were extracted via fitting the $\phi_{\pi^{0}}$ dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying $N^*$ and $\Delta^{*}$ resonances with $M~>~1.6$ GeV. As part of a broad effort to determine the electrocouplings of the $N^{*}$ and $\Delta^{*}$ resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the $N \pi$ and $\pi^{+}\pi^{-} p$ channels.Comment: 21 pages, 24 figure
H Aihara - One of the best experts on this subject based on the ideXlab platform.
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study of pi 0 pair production in single tag two photon collisions
Physical Review D, 2016Co-Authors: M Masuda, S Uehara, Y Watanabe, H Nakazawa, A Abdesselam, I Adachi, H Aihara, Al S Said, D M Asner, H AtmacanAbstract:We report a measurement of the differential cross section of pi(0) pair production in single-tag two-photon collisions, gamma*gamma -> pi(0) pi(0), in e(+) e(-) scattering. The cross section is measured for Q(2) up to 30 GeV2, where Q(2) is the negative of the invariant mass squared of the tagged photon, in the kinematic range 0.5 GeV < W < 2.1 GeV and vertical bar cos theta*vertical bar < 1.0 for the total energy and pion scattering angle, respectively, in the gamma*gamma Center-of-Mass System. The results are based on a data sample of 759 fb(-1) collected with the Belle detector at the KEKB asymmetric-energy e(+) e(-) collider. The transition form factor of the f(0)(980) and that of the f(2)(1270) with the helicity-0, -1, and -2 components separately are measured for the first time and are compared with theoretical calculations.
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high statistics study of ηπ0 production in two photon collisions
Physical Review D, 2009Co-Authors: S Uehara, Y Watanabe, H Nakazawa, I Adachi, H Aihara, K Arinstein, V Aulchenko, A M BakichAbstract:The differential cross section for the process γγ→η π0 has been measured in the kinematic range 0.84GeV
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high statistics study of neutral pion pair production in two photon collisions
Physical Review D, 2009Co-Authors: S Uehara, Y Watanabe, H Nakazawa, H Aihara, K Arinstein, V Aulchenko, A M Bakich, E L Barberio, K Belous, V BhardwajAbstract:The differential cross sections for the process gamma gamma -> pi(0)pi(0) have been measured in the kinematic range 0.6 GeV < W < 4.1 GeV, vertical bar cos theta* vertical bar < 0.8 in energy and pion scattering angle, respectively, in the gamma gamma Center-of-Mass System. The results are based on a 223 fb(-1) data sample collected with the Belle detector at the KEKB e(+)e(-) collider. The differential cross sections are fitted in the energy region 1.7 GeV < W < 2.5 GeV to confirm the two-photon production of two pions in the G wave. In the higher-energy region, we observe production of the chi(c0) charmonium state and obtain the product of its two-photon decay width and branching fraction to pi(0)pi(0). We also compare the observed angular dependence and ratios of cross sections for neutral-pion and charged-pion pair production to QCD models. The energy and angular dependence above 3.1 GeV are compatible with those measured in the pi(+)pi(-) channel, and in addition we find that the cross section ratio, sigma(pi(0)pi(0))/sigma(pi(+)pi(-)), is 0.32 +/- 0.03 +/- 0.05 on average in the 3.1-4.1 GeV region.
H Nakazawa - One of the best experts on this subject based on the ideXlab platform.
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study of pi 0 pair production in single tag two photon collisions
Physical Review D, 2016Co-Authors: M Masuda, S Uehara, Y Watanabe, H Nakazawa, A Abdesselam, I Adachi, H Aihara, Al S Said, D M Asner, H AtmacanAbstract:We report a measurement of the differential cross section of pi(0) pair production in single-tag two-photon collisions, gamma*gamma -> pi(0) pi(0), in e(+) e(-) scattering. The cross section is measured for Q(2) up to 30 GeV2, where Q(2) is the negative of the invariant mass squared of the tagged photon, in the kinematic range 0.5 GeV < W < 2.1 GeV and vertical bar cos theta*vertical bar < 1.0 for the total energy and pion scattering angle, respectively, in the gamma*gamma Center-of-Mass System. The results are based on a data sample of 759 fb(-1) collected with the Belle detector at the KEKB asymmetric-energy e(+) e(-) collider. The transition form factor of the f(0)(980) and that of the f(2)(1270) with the helicity-0, -1, and -2 components separately are measured for the first time and are compared with theoretical calculations.
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high statistics study of ηπ0 production in two photon collisions
Physical Review D, 2009Co-Authors: S Uehara, Y Watanabe, H Nakazawa, I Adachi, H Aihara, K Arinstein, V Aulchenko, A M BakichAbstract:The differential cross section for the process γγ→η π0 has been measured in the kinematic range 0.84GeV
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high statistics study of neutral pion pair production in two photon collisions
Physical Review D, 2009Co-Authors: S Uehara, Y Watanabe, H Nakazawa, H Aihara, K Arinstein, V Aulchenko, A M Bakich, E L Barberio, K Belous, V BhardwajAbstract:The differential cross sections for the process gamma gamma -> pi(0)pi(0) have been measured in the kinematic range 0.6 GeV < W < 4.1 GeV, vertical bar cos theta* vertical bar < 0.8 in energy and pion scattering angle, respectively, in the gamma gamma Center-of-Mass System. The results are based on a 223 fb(-1) data sample collected with the Belle detector at the KEKB e(+)e(-) collider. The differential cross sections are fitted in the energy region 1.7 GeV < W < 2.5 GeV to confirm the two-photon production of two pions in the G wave. In the higher-energy region, we observe production of the chi(c0) charmonium state and obtain the product of its two-photon decay width and branching fraction to pi(0)pi(0). We also compare the observed angular dependence and ratios of cross sections for neutral-pion and charged-pion pair production to QCD models. The energy and angular dependence above 3.1 GeV are compatible with those measured in the pi(+)pi(-) channel, and in addition we find that the cross section ratio, sigma(pi(0)pi(0))/sigma(pi(+)pi(-)), is 0.32 +/- 0.03 +/- 0.05 on average in the 3.1-4.1 GeV region.