1. W. KozaneckiMCC AP meetiing, 20 May 04 Serendipitous measurement of beam-beam tune shift in the LER  Principle  measure colliding tunes (tune tracker data in CRR plot)  dump HER only (RF abort)  LER tunes move   (no beam-beam)   or  (tune feed-forward senses I HER = 0 + small LER beam loss)  measure single-beam LER tunes and subtract variation in tune multiknobs (from MKB history). This yields  unshifted LER tunes  beam-beam tune shift   x, y (related to, but different from, beam- beam parameter    x, y )  Experimental details: PEP-II e-log, 15 May 04 swing shift  data in PHYSICS3_DATA:[pep2.ip.witold.spr04]lumb_t_1_15May W. Kozanecki

2. MCC AP meetiing, 20 May 04 Fast history of beam currents & of LER tune knobs LER_NUX.MKB LER / HER coeff = -210E-7 / 0 LER currentHER current LER_NUY.MKB LER / HER coeff = -150E-7 / 150E-7 Note: how well calibrated are the tune knobs?  

3. W. KozaneckiMCC AP meetiing, 20 May 04 LER tune spectra, in- and out-of-collision In collision (18 May 04) Single beam (27 Feb 04) Well-defined peaks: tune-tracker phase scan unambiguous Where is “the” tune? Could the relationship between phase & peak change significantly ?

4. W. KozaneckiMCC AP meetiing, 20 May 04 Conclusions: LER tunes, raw & corrected LER x tune, rawLER y tune, raw LER x (corrected)LER y (corrected) x LER only =.504 y LER only =.556  x + =.008  y + =.036 x LER, cldg =.512 y LER, cldg =.592 Caveat Relationship between tracker phase & peak? Caveat How well calibrated are the tune knobs?