Xiaorong Zhou Liu Dong Guangshun Simone 09012020 12182021

勤奋, Xiaorong Zhou, Liu Dong, Guangshun, Simone 09/01/2020 12/18/2021 1

Data Sets Jpsi Scan Data 2012 Boss 6. 6. 5. p. 01 12/18/2021 2

12/18/2021 3

Fitting Results 3. 05 Ge. V 3. 0943 Ge. V 3. 0990 Ge. V 12/18/2021 3. 06 Ge. V 3. 083 Ge. V 3. 0952 Ge. V 3. 0958 Ge. V 3. 1015 Ge. V 3. 1055 Ge. V 3. 090 Ge. V 3. 0969 Ge. V 3. 1120 Ge. V 3. 0930 Ge. V 3. 0982 Ge. V 3. 1200 Ge. V 4

BAM-00128 Nomenclature Our Fit function Born cross section for ee to mu+ mu- Channel : Pure EM Contributions Born cross section for ee to 5 pions Born cross section for ee to eta pi+ pi- Relative phase measurement for ee to K+ K 12/18/2021 5

Jpsi Line shape Cross section after correct the Efficiency 12/18/2021 Rate by assuming Eff. Same as 3. 08 Ge. V rscan 6

• • Chi 2_fit modified includes the Error along X-axis is projected along Y-axis. Acc. p. QCD, n=10 in continuum amplitude formula for Jpsi to Bbbar Resume the factor D in the cross section formula to get the reliable results Cross check with fit parameters to measure the Br(J/psi to sigma) Input lineshape Input rough lineshape according to Observed cross section. Using above fitting parameters. 12/18/2021 7

Born Cross section Later to be fit More iterations Required After Ist Iteration For the First Iteration 12/18/2021 8

MC Truth Reconstructed Cut flow 3. 05 3. 08 3. 0930 Tag Sigma 0 7597 total 7496 total 8209 total Decay Length 7214 6983 7834 Chi 2 6875 6621 7563 Lambda cut 6566 6101 7166 Momentum 3402 3781 5384 Sigma 3193 3582 5143 12/18/2021 Why Eff difference? • • At higher energy at Jpsi resonance, we have less ISR photon, get more efficiency. From the MC truth proton and pion momenta and reconstructed momentum of Sigma 0. It is clear that higher energy lessor ISR photon contribution. 9

Back up 12/18/2021 10

After Modification in Fit function • Chi 2_fit modified includes the Error along X-axis is projected along Y-axis. • Acc. p. QCD, n=10 in continuum amplitude formula for Jpsi to Bbbar • Resume the factor D in the cross section formula to get the reliable results • Cross check with fit parameters to measure the Br(J/psi to sigma) 12/18/2021 After Dr. Xiaorong, Dr. liu, and Yadiwang (IHEP). 11

Compare Cross section and Rate 3. 08 shifted -0. 548 Me. V 12/18/2021 3. 08 not shifted 12

MC truth study for proton and pion for tagging sigma 0 Proton 12/18/2021 Pi- 13

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Floating all parameters Energy Spread is fixed Phase is fixed to 0, 45, 90, 135, 180 0 45 135 90 Phase = 90 Degr 180 12/18/2021 15

Fit lineshape results for phase scan • Phase fixed • Energy spread is fixed 12/18/2021 16

To Fit the Line Shape • Fixed phase • Fixed SE Problem with the phase scan Results 12/18/2021 17