MENU 21 Properties of the Λ(145) Measured at CLAS Kei Moriya Reinhard Schumacher
Outline 1 Introduction What is the Λ(145)? Theory of the Λ(145) 2 CLAS Analysis Selecting Decay Channels of Interest Removing Σ (1385) and K Background Fit to Extract Λ(145) Lineshape 3 Results Λ(145) Lineshape Results Λ(145) Cross Section Results Λ(152) Cross Section Results Λ(145), Λ(152), Σ (1385) Cross Section Comparison 4 Conclusion K. Moriya (CMU) Λ(145) lineshape May 21 2 / 19
What is the Λ(145)? **** resonance just below NK threshold J P = 1 2 (experimentally unconfirmed) decays exclusively to (Σπ) past experiments: the lineshape (= invariant Σπ mass distribution) is distorted from a simple Breit-Wigner form what is the nature of this distorted lineshape? normal qqq-baryon resonance dynamically generated resonance in unitary coupled channel approach K. Moriya (CMU) Λ(145) lineshape May 21 3 / 19
J.C. Nacher et al.rphysics Letters B 455 ( 1999) 55 61 Chiral Unitary Coupled Channel Approach equation, and diagrammatically g. 2. t in Fig. 2 is easily evaluated. The process with the j channel in the by means of the vector DjsC1 jp dynamically generate Λ(145) q. e ž j Ý l l l j/ D q D G T, Ž 8. l Chiral Unitary Model Prediction! factorization of the strong ampliw22x for! the + "! related electro- q Fig. 2. DiagrammaticLineshape representationof of #(145) the meson-baryon final nd in % p & state K " " interaction! in thepredicted g p K LŽ 145 to. depend process. on "! as been used. Diagrams where the decay channel E ' 1.7 GeV % the mesons or baryons inside the! J. C. Nacher, E. Oset, H. uppressed at threshold. One can Toki, A. Ramos, Phys. Lett. B ution from the photon attached to Ž.! " the built up of the 455, L 145 55 (1999). resonance, most of them exactly at threshold. This can be open!! " " up at higher energies and the resonance shape! Chiral t the loop involves a term of the is only visible in the p q S y Lagrangian, p y S q, p + S mb FSI channels. + Channel Coupling fž q,q., with fž q,q. L L a scalar The KN production occurs at energies slightly above! I("!) ral is proportional to q and vanulomb gauge constraint, epqs. provides a small background below the resonance. the resonance and the p = {,1,2} not in an L, with isospin one, only isospin eigenstate ll values of the K q!!" momentum Invariant Mass (GeV) It is interesting to I=2 see contributions the different shapes negligible J. C. Nacher et al., Phys. Lett. B455, 55 (1999) of the! the corrections to the cross sec- three ps channels. This Interference can be understood between ini= "! terms d$/dm I (µb/gev) K. Moriya (CMU) Λ(145) lineshape May 21 4 / 19 2 2
I ( ) 1 Difference in Lineshape!!" Invariant Mass (GeV) P $ # d( "! ) 1 1 2 ) T $ T $ Re T T $ O T dm 2 3 6 I & ' & ' (1) 2 () 2 () (1)* (2) # $ d(" (! ) 1 1 2 ) T $ T # Re T T $ O T dm 2 3 6 & ' & ' (1) 2 () 2 () (1)* (2) d("! ) T $ O& T dm 3 I () 2 (2) '! P % I J. C. Nacher et al., Nucl. Phys. B455, 55 difference in lineshapes is due to interference of isospin terms in calculation (T (I) represents amplitude of isospin I term) distortion of the lineshape is connected to underlying QCD amplitudes that generate the Λ(145) this analysis will measure all three Σπ channels K. Moriya (CMU) Λ(145) lineshape May 21 5 / 19
Data From CLAS@JLab CLAS@Jefferson Lab liquid LH 2 target γ + p K + + Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 6 / 19
Data From CLAS@JLab CLAS@Jefferson Lab liquid LH 2 target γ + p K + + Λ(145) real unpolarized photon beam E γ < 3.84 GeV 2B total triggers K. Moriya (CMU) Λ(145) lineshape May 21 6 / 19
Data From CLAS@JLab CLAS@Jefferson Lab liquid LH 2 target γ + p K + + Λ(145) real unpolarized photon beam E γ < 3.84 GeV 2B total triggers measure charged particle p with drift chambers K. Moriya (CMU) Λ(145) lineshape May 21 6 / 19
Data From CLAS@JLab CLAS@Jefferson Lab liquid LH 2 target γ + p K + + Λ(145) real unpolarized photon beam E γ < 3.84 GeV 2B total triggers measure charged particle p with drift chambers timing with TOF walls K. Moriya (CMU) Λ(145) lineshape May 21 6 / 19
γ +p Reaction of Interest K + + Λ(145) Σ + π 52% p(π )π Σ π + 1% 48% (n)π + π Σ π 64% pπ (π, γ) detected particles K +,p,π K +,π +,π missing particle(s) (π ) (π,γ) (n) intermediate hyperon Λ Σ + Σ ( γλ) Σ + Σ kinematic fit yes no yes reaction Σ(1385) Σ(1385), Λ(145), Λ(152) K. Moriya (CMU) Λ(145) lineshape May 21 7 / 19
γ +p Reaction of Interest K + + Λ(145) 33% each? (will be for pure isospin ) Σ + π Σ π + 52% 1% 48% p(π )π (n)π + π Σ π 64% pπ (π, γ) detected particles K +,p,π K +,π +,π missing particle(s) (π ) (π,γ) (n) intermediate hyperon Λ Σ + Σ ( γλ) Σ + Σ kinematic fit yes no yes reaction Σ(1385) Σ(1385), Λ(145), Λ(152) K. Moriya (CMU) Λ(145) lineshape May 21 7 / 19
- Background Σ (1385) Σπ BR(Λπ ) = 88% BR(Σ ± π ) = 6% each measure in Λπ, scale down to each Σπ channel K Σ influence should be small due to branching ratio broad width will overlap with signal subtract off incoherently 1.8 ),π + M(Σ 1.7 1.6 1.5 + data kfit Σ Wbin: 3 2.15 <W< 2.25 only: 7414 1 1 1.4 1.3.6.7.8.9 1 1.1 + - M(K,π ) -1 1 K. Moriya (CMU) Λ(145) lineshape May 21 8 / 19
- Background Σ (1385) Σπ BR(Λπ ) = 88% BR(Σ ± π ) = 6% each measure in Λπ, scale down to each Σπ channel K Σ influence should be small due to branching ratio broad width will overlap with signal subtract off incoherently ) 1.8 1.7 1.6 * K + data kfit Σ Wbin: 3 2.15 <W< 2.25 only: 7414 1,π + M(Σ 1.5 Λ(152) 1 1.4 Λ(145) 1.3.6.7.8.9 1 1.1 + - M(K,π ) -1 1 K. Moriya (CMU) Λ(145) lineshape May 21 8 / 19
- Background Σ (1385) Σπ BR(Λπ ) = 88% BR(Σ ± π ) = 6% each measure in Λπ, scale down to each Σπ channel K Σ influence should be small due to branching ratio broad width will overlap with signal subtract off incoherently ) 1.8 1.7 1.6 kinematic boundary * K + data kfit Σ Wbin: 3 2.15 <W< 2.25 only: 7414 1,π + M(Σ 1.5 Λ(152) 1 1.4 Λ(145) 1.3.6.7.8.9 1 1.1 + - M(K,π ) -1 1 K. Moriya (CMU) Λ(145) lineshape May 21 8 / 19
Σ(1385) is Fit in Λπ Channel (γ + p K + + p + π + π ) counts 2 Wbin: 2 anglebin: 17 18 16 14 12 1 8 6 Λ π threshold 2.5 <W< 2.15 CM.7<cosθ K+ <.8 data example: 1 energy and angle bin out of 15 4 2 1.2 1.25 1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 M(Λ π ) Σ(1385) is fit with templates of MC of Σ(1385) (non-relativistic Breit-Wigner) K + Λ MC very good fit results K. Moriya (CMU) Λ(145) lineshape May 21 9 / 19
Σ(1385) is Fit in Λπ Channel (γ + p K + + p + π + π ) counts 2 Wbin: 2 anglebin: 17 18 16 14 12 1 8 6 Λ π threshold 2.5 <W< 2.15 CM.7<cosθ K+ <.8 data Σ(1385) MC example: 1 energy and angle bin out of 15 4 2 1.2 1.25 1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 M(Λ π ) Σ(1385) is fit with templates of MC of Σ(1385) (non-relativistic Breit-Wigner) K + Λ MC very good fit results K. Moriya (CMU) Λ(145) lineshape May 21 9 / 19
Σ(1385) is Fit in Λπ Channel (γ + p K + + p + π + π ) counts 2 Wbin: 2 anglebin: 17 18 16 14 12 1 8 6 Λ π threshold 2.5 <W< 2.15 CM.7<cosθ K+ <.8 data Σ(1385) MC *+ K Λ MC example: 1 energy and angle bin out of 15 4 2 1.2 1.25 1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 M(Λ π ) Σ(1385) is fit with templates of MC of Σ(1385) (non-relativistic Breit-Wigner) K + Λ MC very good fit results K. Moriya (CMU) Λ(145) lineshape May 21 9 / 19
Σ(1385) is Fit in Λπ Channel (γ + p K + + p + π + π ) counts 2 Wbin: 2 anglebin: 17 18 16 14 12 1 8 6 Λ π threshold 2.5 <W< 2.15 CM.7<cosθ K+ <.8 data Σ(1385) MC *+ K Λ MC sum of MC χ 2 /ndf: 1.6 example: 1 energy and angle bin out of 15 4 2 1.2 1.25 1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 M(Λ π ) Σ(1385) is fit with templates of MC of Σ(1385) (non-relativistic Breit-Wigner) K + Λ MC very good fit results K. Moriya (CMU) Λ(145) lineshape May 21 9 / 19
Σ(1385) Cross Section From Λπ Channel [µb] dσ c.m. dcosθ K+ 1.9.8.7.6.5.4 2.5<W<2.15 1.77<E γ <1.994 5th order Legendre fit.3.2.1-1 -.8 -.6 -.4 -.2.2.4.6.8 1 c.m. cosθ K+ Preliminary scale by branching ratio and acceptance into each Σπ channel BR(Λπ) = 89% BR(Σπ) = 11% Σ π channel does not have Σ(1385) K. Moriya (CMU) Λ(145) lineshape May 21 1 / 19
Fit to Lineshape With MC Templates 6 5 4 + Σ p π Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data counts 3 2 example: 1 energy and angle bin out of 15 1 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 11 / 19
Fit to Lineshape With MC Templates counts 6 5 4 3 2 + Σ p π Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data Σ(1385) MC example: 1 energy and angle bin out of 15 1 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 11 / 19
Fit to Lineshape With MC Templates counts 6 5 4 3 2 + Σ p π Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data Σ(1385) MC Λ(145) MC ver.1 example: 1 energy and angle bin out of 15 1 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 11 / 19
Fit to Lineshape With MC Templates counts 6 5 4 3 2 + Σ p π Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data Σ(1385) MC Λ(145) MC ver.1 Λ(152) MC example: 1 energy and angle bin out of 15 1 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 11 / 19
Fit to Lineshape With MC Templates counts 6 5 4 3 2 + Σ p π Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data Σ(1385) MC Λ(145) MC ver.1 Λ(152) MC * + K Σ example: 1 energy and angle bin out of 15 1 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 11 / 19
Fit to Lineshape With MC Templates counts 6 5 4 3 2 + Σ p π Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data Σ(1385) MC Λ(145) MC ver.1 Λ(152) MC * + K Σ sum of MC χ 2 /ndf: 4.16 example: 1 energy and angle bin out of 15 1 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 11 / 19
Fit to Lineshape With MC Templates counts 6 5 4 3 2 + Σ p π Λ(145) MC ver.2 Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data Σ(1385) MC Λ(145) MC ver.1 Λ(152) MC * + K Σ sum of MC χ 2 /ndf: 2.9 example: 1 energy and angle bin out of 15 1 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 11 / 19
Fit to Lineshape With MC Templates counts 6 5 4 3 2 + Σ p π Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data residual example: 1 energy and angle bin out of 15 1 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 11 / 19
Results of Lineshape dσ/dm [µb/gev] 2.5 1.77<E γ <1.99 2.5<W<2.15 2 Σ π thresholds 1.5 1 + - Σ π weighted average Σ - π + Σ π PDG Breit-Wigner Preliminary.5 1.3 1.4 1.5 Σ π Invariant Mass [GeV] lineshapes do appear different for each Σπ decay mode Σ + π decay mode has peak at highest mass, narrow than Σ π + lineshapes are summed over acceptance region of CLAS difference is less prominent at higher energies K. Moriya (CMU) Λ(145) lineshape May 21 12 / 19
Results of Lineshape 1 2.47<E γ <2.73 2.35<W<2.45 + - Σ π weighted average Σ - π + Σ π PDG Breit-Wigner dσ/dm [µb/gev].8.6.4 Σ π thresholds Preliminary.2 1.3 1.4 1.5 Σ π Invariant Mass [GeV] lineshapes do appear different for each Σπ decay mode Σ + π decay mode has peak at highest mass, narrow than Σ π + lineshapes are summed over acceptance region of CLAS difference is less prominent at higher energies K. Moriya (CMU) Λ(145) lineshape May 21 12 / 19
Results of Lineshape dσ/dm [µb/gev].4.35.3.25.2.15.1.5 3.27<E γ <3.56 2.65<W<2.75 Σ π thresholds + - Σ π weighted average Σ - π + Σ π PDG Breit-Wigner 1.3 1.4 1.5 Σ π Invariant Mass [GeV] Preliminary lineshapes do appear different for each Σπ decay mode Σ + π decay mode has peak at highest mass, narrow than Σ π + lineshapes are summed over acceptance region of CLAS difference is less prominent at higher energies K. Moriya (CMU) Λ(145) lineshape May 21 12 / 19
d$/dm I (µb/gev)! " Theory Prediction From Chiral Unitary Approach! # " $ Chiral Unitary Model Prediction! Lineshape of #(145)! + "! % p & K "! predicted to depend on "! decay channel!" Invariant Mass (GeV) E ' 1.7 GeV %! J. C. $ # d( "! Nacher, ) 1 E. Oset, H. (1) 2 1 () 2 2 ) () (1)* (2) T $ T $ Re Toki, A. Ramos, Phys. Lett. & T T B ' $ O& T ' dm 2 3 I 6! " # $ 455, 55 (1999).!! " " d(" (! ) 1 (1) 2 1 () 2 2 ) () (1)* (2) T $ T # Re & T T ' $ O& T '! dm 2 3 I Chiral Lagrangian + 6mB FSI d(" ( +! Channel ) Coupling 1 2 ) () (2) T $ O& T ' dm 3 I! I("!) = {,1,2} not in an isospin eigenstate!!" Invariant Mass (GeV) I=2 contributions negligible! Interference between I= "! d$ ("! ) 1 (1) 2 1 () 2 2 % Re () (1)* (2) T " T " # T T $ " O # T $ and I=1 amplitudes modifies ΣdM 2 3 I π + decay mode6 peaks at highest mass, most distributions narrow! " d$ ("! ) 1 (1) 2 1 () 2 2 % Re () (1)* (2) T " T! # T T $ " O # T difference $ dm 2 in3lineshapes I 6 is due to interference of isospin terms in d$ ("! ) 1 () 2 calculation % (T (I) (2) T represents " amplitude O # T $ of isospin I term) dm 3 I we have started trying fits to the resonance amplitudes J. C. Nacher et al., Nucl. Phys. B455, 55 Apr-2-29, NSTAR29, Beijing R. A. Schumacher, Carnegie Mellon University 1 d(/dm I (* K. Moriya (CMU) Λ(145) lineshape May 21 13 / 19
Isospin Decomposition Separate {! " # $,! % # %,! $ # " } into I= and I=1 amplitude contributions T ( {!# } Tˆ & p () () I ' T ( {!# } Tˆ & p (1) (1) I ' 1 T ( {!# } Tˆ & p (2) (2) I ' 2 1 1 2 A ' T " T $ T! 3 2 6 T * 2 1 () 2 A ' T! # 3 2 1 () 2 1 (1) 2 2 () (1) A $ " ' T " T " T T cos *! 3 2 6 2 () 2 (1) 2 () (1) " $ cos ) # 1 ) # 1 +! c, 2 p m f 2 d-. ( ) ' ( I, I,) T " ( I, I 1,) T " ( I, I 2,) T dm # W p W 2 16 ( ) i (,1,2) (,1,2) ( )' 2 2 T m g () (1) (2) 3! 3# 3! 3# 3! 3# / m / ( m $ m ) $ im( q) / ' 2 q/ m ( m) ' qm ( ) q!1#1phase space factor Mass-dependent width for relativistic Breit Wigner K. Moriya (CMU) Λ(145) lineshape May 21 14 / 19
Isospin Decomposition " # $! $! I= contribution Preliminary # " $! I=1 contributions K. Moriya (CMU) Λ(145) lineshape May 21 15 / 19
Λ(145) Differential Cross Section Results.25 1.99<E γ <2.23 [µb] dcosθ dσ.2.15.1.5 2.15<W<2.25 Preliminary Σ + π Σ π Σ π + total/3-1 -.8 -.6 -.4 -.2.2.4.6.8 1 c.m. cosθ K+ lines are fits with 6 rd order Legendre polynomials clear turnover of Σ + π channel at forward angles theory: contact term only, no angular dependence for interference experiment: able to see strong isospin AND angular interference effect K. Moriya (CMU) Λ(145) lineshape May 21 16 / 19
Λ(145) Differential Cross Section Results.18.16 3.27<E γ <3.56 [µb] dcosθ dσ.14.12.1.8.6.4 2.65<W<2.75 Preliminary Σ + π Σ π Σ π + total/3.2-1 -.8 -.6 -.4 -.2.2.4.6.8 1 c.m. cosθ K+ lines are fits with 6 rd order Legendre polynomials clear turnover of Σ + π channel at forward angles theory: contact term only, no angular dependence for interference experiment: able to see strong isospin AND angular interference effect K. Moriya (CMU) Λ(145) lineshape May 21 16 / 19
Λ(152) Differential Cross Section Comparison ] -2 [µb/gev d dt σ 1.2 1.8.6.4.2 Σ π average: 2.474<E - p K average: E - p K average: E - p K average: E - p K average: E - p K average: E Preliminary <2.73 γ =2.44 γ =2.53 γ =2.565 γ =2.628 γ =2.69 γ.5 1 1.5 2 2.5 2 t-t [GeV ] binning is in t t min good agreement with pk channel from CLAS (unpublished) data provided by de Vita et al. (INFN Genova) K. Moriya (CMU) Λ(145) lineshape May 21 17 / 19
Comparison of Σ(1385)/Λ(145)/Λ(152) Cross Sections 1.2 [µb] dcosθ dσ 1.8.6.4 1.99<E γ <2.23 2.15<W<2.25 Λ(145) sum of Σ π modes Σ(1385) total from Λ π Λ(152) average of 3 Σ π Preliminary.2-1 -.8 -.6 -.4 -.2.2.4.6.8 1 c.m. cosθ K+ lines are fits with 5 th order Legendre polynomials K. Moriya (CMU) Λ(145) lineshape May 21 18 / 19
Comparison of Σ(1385)/Λ(145)/Λ(152) Cross Sections [µb] dcosθ dσ.8.7.6.5.4.3 3.27<E γ <3.56 2.65<W<2.75 Λ(145) sum of Σ π modes Σ(1385) total from Λ π Λ(152) average of 3 Σ π Preliminary.2.1-1 -.8 -.6 -.4 -.2.2.4.6.8 1 c.m. cosθ K+ lines are fits with 5 th order Legendre polynomials K. Moriya (CMU) Λ(145) lineshape May 21 18 / 19
Conclusion difference in lineshapes observed difference in dσ/dcosθk c.m. behavior observed + doing our own isospin decomposition of resonance amplitudes systematics under study strong dynamical effects being observed for the Λ(145) hoping to finalize analysis soon K. Moriya (CMU) Λ(145) lineshape May 21 19 / 19
effect of kinematic fit on resolution example in 1 bin: neutron combined with π ± reconstructs Σ ± project on each axis, select ±2σ, exclude other hyperon diagonal band (K from π + π ) is also excluded (without kinematic fit) 2 - # Wbin: 2 tbin: 18 2.5 <W< 2.15 -.27<t<-.135 missing n: 26355 nominal ±2" lines kfit ±2" lines 1.8 M 2 (! +,n) 1.6 1.4 + # 1.2 1.2 1.4 - M 2 1.6 (!,n) 1.8 2 K. Moriya (CMU) Λ(145) lineshape May 21 1 / 5
effect of kinematic fit on resolution example in 1 bin: neutron combined with π ± reconstructs Σ ± project on each axis, select ±2σ, exclude other hyperon diagonal band (K from π + π ) is also excluded (with kinematic fit) 2 - # Wbin: 2 tbin: 18 2.5 <W< 2.15 -.27<t<-.135 CL(n)>1: 2448 nominal ±2" lines kfit ±2" lines 1.8 M 2 (! +,n) 1.6 1.4 + # 1.2 1.2 1.4 - M 2 1.6 (!,n) 1.8 2 K. Moriya (CMU) Λ(145) lineshape May 21 1 / 5
Fit to Lineshape With MC Templates counts 4 35 3 25 2 15 - - Σ n π Wbin: 3 anglebin: 17 2.15 <W< 2.25 CM.7<cosθ K+ <.8 data Σ(1385) MC Λ(145) MC Λ(152) MC * + K Σ sum of MC χ 2 /ndf: 2.62 example: 1 energy and angle bin out of 15 1 5 1.3 1.4 1.5 1.6 1.7 1.8 Σ π Invariant Mass (GeV) subtract off Σ(1385), Λ(152), K + Σ π + phase space assigned the remaining contribution to the Λ(145) K. Moriya (CMU) Λ(145) lineshape May 21 2 / 5
Comparison of Lineshapes for Two Σ + Channels dσ/dm [µb/gev] 2.5 1.77<E γ <1.99 2 2.5<W<2.15 1.5 1.5 Preliminary + - - Σ π p π π + - - Σ π n π + π weighted average PDG Breit-Wigner 1.3 1.4 1.5 Σ π Invariant Mass [GeV] K. Moriya (CMU) Λ(145) lineshape May 21 3 / 5
Comparison of Lineshapes for Two Σ + Channels dσ/dm [µb/gev] 1 2.47<E γ <2.73 2.35<W<2.45.8.6.4.2 Preliminary + - - Σ π p π π + - - Σ π n π + π weighted average PDG Breit-Wigner 1.3 1.4 1.5 Σ π Invariant Mass [GeV] K. Moriya (CMU) Λ(145) lineshape May 21 3 / 5
Comparison of Lineshapes for Two Σ + Channels dσ/dm [µb/gev].4.35.3.25.2.15.1.5 3.27<E γ <3.56 2.65<W<2.75 Preliminary + - - Σ π p π π + - - Σ π n π + π weighted average PDG Breit-Wigner 1.3 1.4 1.5 Σ π Invariant Mass [GeV] K. Moriya (CMU) Λ(145) lineshape May 21 3 / 5
Λ(145) Comparison of Two Σ + Channels.3 [µb] dcosθ dσ.25.2.15.1 Wbin: 2 1.77<E γ <1.99 2.5<W<2.15 + - - Σ π p π π + - - Σ π n π + π + - weighted Σ π Preliminary.5 χ 2 from fit to 6th Legendre 1.322 1.433-1 -.8 -.6 -.4 -.2.2.4.6 1.164.8 1 CM cosθ K+ K. Moriya (CMU) Λ(145) lineshape May 21 4 / 5
Λ(145) Comparison of Two Σ + Channels.24 [µb] dcosθ dσ.22.2.18.16.14.12.1.8.6 Wbin: 5 2.47<E γ <2.73 2.35<W<2.45 + - - Σ π p π π + - - Σ π n π + π + - weighted Σ π Preliminary.4 χ 2 from fit to 6th Legendre.2 2.462 1.73-1 -.8 -.6 -.4 -.2.2.4.6 4.22.8 1 CM cosθ K+ K. Moriya (CMU) Λ(145) lineshape May 21 4 / 5
Λ(145) Comparison of Two Σ + Channels.18 [µb] dcosθ dσ.16.14.12.1.8.6 Wbin: 8 3.27<E γ <3.56 2.65<W<2.75 + - - Σ π p π π + - - Σ π n π + π + - weighted Σ π Preliminary.4.2 χ 2 from fit to 6th Legendre 3.479 2.856-1 -.8 -.6 -.4 -.2.2.4.6 1.13.8 1 CM cosθ K+ K. Moriya (CMU) Λ(145) lineshape May 21 4 / 5
Λ(152) Comparison of Two Σ + Channels 1.8 1.77<E γ <1.99 2.5<W<2.15 Preliminary [µb] dcosθ dσ.6.4 + - - Σ π p π π + - - Σ π n π + π + - weighted Σ π.2-1 -.8 -.6 -.4 -.2.2.4.6.8 1 CM cosθ K+ K. Moriya (CMU) Λ(145) lineshape May 21 5 / 5
Λ(152) Comparison of Two Σ + Channels 1.9.8.7 2.47<E γ <2.73 2.35<W<2.45 Preliminary [µb] dcosθ dσ.6.5.4.3 + - - Σ π p π π + - - Σ π n π + π + - weighted Σ π.2.1-1 -.8 -.6 -.4 -.2.2.4.6.8 1 CM cosθ K+ K. Moriya (CMU) Λ(145) lineshape May 21 5 / 5
Λ(152) Comparison of Two Σ + Channels.9 [µb] dcosθ dσ.8.7.6.5.4.3 3.27<E γ <3.56 2.65<W<2.75 + - - Σ π p π π + - - Σ π n π + π + - weighted Σ π Preliminary.2.1-1 -.8 -.6 -.4 -.2.2.4.6.8 1 CM cosθ K+ K. Moriya (CMU) Λ(145) lineshape May 21 5 / 5